Switch detailed rule differences to info (file) output

[JoshuaKGoldberg]

🚀 Feature Request

Rule behavior changes are pretty verbose in a lot of configurations. They're the only category of verbose, many-line output with all output written to stdout. Others log a small summary to stdout and put details in the log file.

Existing Behavior

As of #246, typical CLI output might look like this:

λ tslint-to-eslint-config --comments *.ts
✨ 90 rules replaced with their ESLint equivalents. ✨

❗ 7 ESLint rules behave differently from their TSLint counterparts ❗
  * camelcase:
    - Leading undescores in variable names will now be ignored.
    - ESLint's camel-case rule does not allow pascal or snake case variable names. Those cases are reserved for class names and static methods.
  * no-underscore-dangle:
    - Leading and trailing underscores (_) on identifiers will now be ignored.
  * space-before-function-paren:
    - Option "method" is not supported by ESLint.
    - Option "constructor" is not supported by ESLint.
  * no-console:
    - Custom console methods, if they exist, will no longer be allowed.
  * import/no-extraneous-dependencies:
    - ESLint does not support whitelisting modules
  * no-invalid-this:
    - Functions in methods will no longer be ignored.
  * no-unused-expressions:
    - The TSLint optional config "allow-new" is the default ESLint behavior and will no longer be ignored.

❌ 1 error thrown. ❌
  Check ./tslint-to-eslint-config.log for details.
️
❓ 1 rule does not yet have an ESLint equivalent ❓
  See generated log file; defaulting to eslint-plugin-tslint for it.

⚡ 4 packages are required for new ESLint rules. ⚡
  eslint-plugin-import
  import
  eslint-plugin-jsdoc
  prefer-arrow

♻ 2 files of TSLint comment directives converted to ESLint. ♻

✅ All is well! ✅

Change Proposal

Let's print the typical "see *.log for details" file instead.