`--quiet` to suppress boilerplate

[rgoldberg]

Please add a --quiet flag to suppress boilerplate, e.g.:

## outputs 4 boilerplate lines
$ markdownlint-cli2 '**/*.md'
markdownlint-cli2 v0.17.2 (markdownlint v0.37.4)
Finding: **/*.md !.build
Linting: 4 file(s)
Summary: 0 error(s)

## outputs nothing
$ markdownlint-cli2 --quiet '**/*.md'

[DavidAnson]

You can already do this via configuration with noBanner and noProgress as documented here: https://github.com/DavidAnson/markdownlint-cli2?tab=readme-ov-file#markdownlint-cli2jsonc

[rgoldberg]

@DavidAnson Thanks for the info. That works for me.

You might want to mention in the docs for each of those 2 settings that the 2 together can simulate --quiet from other linters.

I just did a text find for quiet in the README.md because I didn't have time to read all the docs when I was looking into switching from mdl 1 to mdl 2; it might help others find these settings if --quiet were referenced in their docs.

Is there any way that you'd support automatically reading .markdownlint-cli2.yml in addition to .markdownlint-cli2.yaml? Note the different extensions. All my existing YAML files use .yml, and I'd prefer to keep everything consistent. I don't know if third-party tools will work with .yaml, so I'd prefer to just use .yml.

Lastly, Is the following top-level property the correct way to specify the JSON Schema in a YAML file? Is it OK without quotes?

$schema: https://raw.githubusercontent.com/DavidAnson/markdownlint-cli2/main/schema/markdownlint-cli2-config-schema.json

Thanks for all the help, and for markdownlint*.

[DavidAnson]

Glad that works! I'll look at what do you suggest soon.

For file extension support, there is a discussion here that outlines my current thinking: #392

For associating schemas in YAML, it appears to be done differently (assuming this tool is to be trusted - which I do without evidence to the contrary): https://github.com/redhat-developer/vscode-yaml?tab=readme-ov-file#associating-a-schema-in-the-yaml-file