README: use one line per sentence (#496)

This commit only adds newlines. It doesn't change how the document is
rendered, but it makes diffs more obvious.

This is one of Exercism's preferences for Markdown - see:
https://github.com/exercism/docs/blob/79a253f42bfc/building/markdown/markdown.md#one-sentence-per-line

README.md

@@ -50,9 +50,11 @@ Global options:
 
 ## `configlet lint`
 
-The primary function of configlet is to do _linting_: checking if a track's configuration files are properly structured - both syntactically and semantically. Misconfigured tracks may not sync correctly, may look wrong on the website, or may present a suboptimal user experience, so configlet's guards play an important part in maintaining the integrity of Exercism.
+The primary function of configlet is to do _linting_: checking if a track's configuration files are properly structured - both syntactically and semantically.
+Misconfigured tracks may not sync correctly, may look wrong on the website, or may present a suboptimal user experience, so configlet's guards play an important part in maintaining the integrity of Exercism.
 
-The `configlet lint` command is still under development. The list of currently implemented checks can be found [here](https://github.com/exercism/configlet/issues/249).
+The `configlet lint` command is still under development.
+The list of currently implemented checks can be found [here](https://github.com/exercism/configlet/issues/249).
 
 ## `configlet sync`
 
@@ -66,15 +68,21 @@ There is also one kind of data that can be populated from the track-level `confi
 
 We describe the checking and updating of these data kinds in individual sections below, but as a quick summary:
 
-- `configlet sync` only operates on exercises that exist in the track-level `config.json` file. Therefore if you are implementing a new exercise on a track and want to add the initial files with `configlet sync`, please add the exercise to the track-level `config.json` file first. If the exercise is not yet ready to be user-facing, please set its `status` value to `wip`.
+- `configlet sync` only operates on exercises that exist in the track-level `config.json` file.
+  Therefore if you are implementing a new exercise on a track and want to add the initial files with `configlet sync`, please add the exercise to the track-level `config.json` file first.
+  If the exercise is not yet ready to be user-facing, please set its `status` value to `wip`.
 - A plain `configlet sync` makes no changes to the track, and checks every data kind for every exercise.
 - To operate on a subset of data kinds, use some combination of the `--docs`, `--filepaths`, `--metadata`, and `--tests` options.
 - To interactively update data on the track, use the `--update` option.
 - To non-interactively update docs, filepaths, and metadata on the track, use `--update --yes`.
 - To non-interactively include every unseen test for a given exercise, use e.g. `--update --tests include --exercise prime-factors`.
 - To skip downloading the `problem-specifications` repo, add `--offline --prob-specs-dir /path/to/local/problem-specifications`
-- Note that `configlet sync` tries to maintain the key order in exercise `.meta/config.json` files when updating. To write these files in a canonical form without syncing, please use the `configlet fmt` command. However, `configlet sync` _does_ add (possibly empty) required keys (`authors`, `files`, `blurb`) when they are missing. This is less "sync-like", but more ergonomic: when implementing a new exercise, you can use `sync` to create a starter `.meta/config.json` file.
-- `configlet sync` removes keys that are not in the spec. Custom key/value pairs are still supported: they must be written inside a JSON object named `custom`.
+- Note that `configlet sync` tries to maintain the key order in exercise `.meta/config.json` files when updating.
+  To write these files in a canonical form without syncing, please use the `configlet fmt` command.
+  However, `configlet sync` _does_ add (possibly empty) required keys (`authors`, `files`, `blurb`) when they are missing.
+  This is less "sync-like", but more ergonomic: when implementing a new exercise, you can use `sync` to create a starter `.meta/config.json` file.
+- `configlet sync` removes keys that are not in the spec.
+  Custom key/value pairs are still supported: they must be written inside a JSON object named `custom`.
 - The exit code is 0 when all the seen data are synced when configlet exits, and 1 otherwise.
 
 Note that in `configlet` releases `4.0.0-alpha.34` and earlier, the `sync` command operated only on tests.
@@ -140,7 +148,9 @@ configlet sync --metadata -uy -e prime-factors
 
 ### Tests
 
-If a track implements an exercise for which test data exists in the [problem-specifications repo](https://github.com/exercism/problem-specifications), the exercise _must_ contain a `.meta/tests.toml` file. The goal of the `tests.toml` file is to keep track of which tests are implemented by the exercise. Tests in this file are identified by their UUID and each test has a boolean value that indicates if it is implemented by that exercise.
+If a track implements an exercise for which test data exists in the [problem-specifications repo](https://github.com/exercism/problem-specifications), the exercise _must_ contain a `.meta/tests.toml` file.
+The goal of the `tests.toml` file is to keep track of which tests are implemented by the exercise.
+Tests in this file are identified by their UUID and each test has a boolean value that indicates if it is implemented by that exercise.
 
 A `tests.toml` file has this format:
 
@@ -168,7 +178,8 @@ include = false
 comment = "excluded because we don't want to add error handling to the exercise"
 ```
 
-In this case, the track has chosen to implement two of the three available tests. If a track uses a _test generator_ to generate an exercise's test suite, it _must_ use the contents of the `tests.toml` file to determine which tests to include in the generated test suite.
+In this case, the track has chosen to implement two of the three available tests.
+If a track uses a _test generator_ to generate an exercise's test suite, it _must_ use the contents of the `tests.toml` file to determine which tests to include in the generated test suite.
 
 To check every Practice Exercise `tests.toml` file for available tests updates (exiting with a non-zero exit code if there is at least one test case that appears in the exercise's canonical data, but not in the `tests.toml`):
 
@@ -186,7 +197,8 @@ For each missing test, this prompts the user to choose whether to include/exclud
 Configlet writes an exercise's `tests.toml` file when the user has finished making choices for that exercise.
 This means that you can terminate configlet at a prompt (for example, by pressing Ctrl-C in the terminal) and only lose the syncing decisions for at most one exercise.
 
-To non-interactively include every unseen test case, use `--tests include`. For example, to do so for an exercise named `prime-factors`:
+To non-interactively include every unseen test case, use `--tests include`.
+For example, to do so for an exercise named `prime-factors`:
 
 ```shell
 configlet sync --tests include -u -e prime-factors
@@ -222,11 +234,14 @@ configlet sync --filepaths -uy -e prime-factors
 
 ### Using `sync` when adding a new exercise to a track
 
-The `sync` command is useful when adding a new exercise to a track. If you are adding a Practice Exercise named `foo` that exists in `problem-specifications`, one possible workflow is:
+The `sync` command is useful when adding a new exercise to a track.
+If you are adding a Practice Exercise named `foo` that exists in `problem-specifications`, one possible workflow is:
 
-1. Manually add an entry to the track-level `config.json` file for the exercise `foo`. This makes the exercise visible to `configlet sync`.
+1. Manually add an entry to the track-level `config.json` file for the exercise `foo`.
+   This makes the exercise visible to `configlet sync`.
 1. Run `configlet sync --docs --filepaths --metadata -uy -e foo` to create the exercise's documentation, and a starter `.meta/config.json` file with populated `files`, `blurb`, and perhaps `source` and `source_url` values.
-1. Edit the exercise `.meta/config.json` file as desired. For example, add yourself to the `authors` array.
+1. Edit the exercise `.meta/config.json` file as desired.
+   For example, add yourself to the `authors` array.
 1. Run `configlet sync --tests include -u -e foo` to create a `.meta/tests.toml` file with every test included.
 1. View that `.meta/tests.toml` file, and add `include = false` to any test case that the exercise will not implement.
 1. Implement the tests for the exercise to match those included in `.meta/tests.toml`.
@@ -325,13 +340,15 @@ The exit code is 0 when every seen exercise has a formatted `.meta/config.json`
 
 ## `configlet uuid`
 
-Each exercise and concept has a [UUID](https://en.wikipedia.org/wiki/Universally_unique_identifier), which must only appear once across all of Exercism. It must be a valid version 4 UUID (compliant with RFC 4122) in the canonical textual representation, which means that it must match the below regular expression:
+Each exercise and concept has a [UUID](https://en.wikipedia.org/wiki/Universally_unique_identifier), which must only appear once across all of Exercism.
+It must be a valid version 4 UUID (compliant with RFC 4122) in the canonical textual representation, which means that it must match the below regular expression:
 
 ```text
 ^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$
 ```
 
-You can run `configlet uuid` to output a new, appropriate UUID. There is also the `-n, --num` option for outputting multiple new UUIDs:
+You can run `configlet uuid` to output a new, appropriate UUID.
+There is also the `-n, --num` option for outputting multiple new UUIDs:
 
 ```console
 $ configlet uuid --num 5
@@ -344,7 +361,9 @@ e42b94bb-9c90-47f2-aebb-03cdbc27bf3b
 
 ## `configlet generate`
 
-Each concept exercise and concept have an `introduction.md` file. If you want the exercise's introduction to include the concept's introduction verbatim, you can create a `introduction.md.tpl` file to achieve this. This file may use a placeholder to refer to the concept's introduction, so that the information is not duplicated.
+Each concept exercise and concept have an `introduction.md` file.
+If you want the exercise's introduction to include the concept's introduction verbatim, you can create a `introduction.md.tpl` file to achieve this.
+This file may use a placeholder to refer to the concept's introduction, so that the information is not duplicated.
 
 Concept placeholders must use the following format:
 
@@ -358,13 +377,17 @@ For example, if the track has a concept named `floating-point-numbers` then an `
 %{concept:floating-point-numbers}
 ```
 
-You can run `configlet generate` to generate the exercise's `introduction.md` for any exercise that has an `introduction.md.tpl` file. The generated `introduction.md` is identical to the `introduction.md.tpl`, except that concept placeholders are replaced with the contents of the concept's `introduction.md` file (minus its top-level heading). In the future, `configlet generate` will also increment the level of other headings by 1 (e.g. from `## My Heading` to `### My Heading`), but this is not yet implemented.
+You can run `configlet generate` to generate the exercise's `introduction.md` for any exercise that has an `introduction.md.tpl` file.
+The generated `introduction.md` is identical to the `introduction.md.tpl`, except that concept placeholders are replaced with the contents of the concept's `introduction.md` file (minus its top-level heading).
+In the future, `configlet generate` will also increment the level of other headings by 1 (e.g. from `## My Heading` to `### My Heading`), but this is not yet implemented.
 
 ## Use in your track
 
-Each track should have a `bin/fetch-configlet` script, and might have a `bin/fetch-configlet.ps1` script too. The first is a bash script, and the second is a PowerShell script.
+Each track should have a `bin/fetch-configlet` script, and might have a `bin/fetch-configlet.ps1` script too.
+The first is a bash script, and the second is a PowerShell script.
 
-Running one of these scripts downloads the latest version of configlet to the `bin` directory. You can then use configlet by running `bin/configlet` or `bin/configlet.exe` respectively.
+Running one of these scripts downloads the latest version of configlet to the `bin` directory.
+You can then use configlet by running `bin/configlet` or `bin/configlet.exe` respectively.
 
 ## Contributing