Add markdownlint settings

[o-l-a-v]

Summary

In VSCode with Markdownlint (https://marketplace.visualstudio.com/items?itemName=DavidAnson.vscode-markdownlint) and default rules enabled, it'd autocorrect a few things that do not seem to be what the project wants for its doc. For instance:

MD014 - Dollar signs used before commands without showing output

Would corrent

```console
$ winget install --id=astral-sh.uv  -e
```

to

```console
winget install --id=astral-sh.uv  -e
```

MD046 - Code block style

Says installation.md uses inconsistent code block style.

Seems the doc must use it for it to look good with mkdocs?

Test Plan

Affects developer experience.

[zanieb]

I'm a little hesitant to add configuration for tools we're not using / enforcing. Does markdownlint catch anything we'd want to enforce?

[o-l-a-v]

Very understandable. 😊

What IDE do contributors typically use, and do they lint markdown while editing in the IDE itself? How is that linting configured? I like immediate feedback vs. waiting for CI/CD tests. Markdownlint seems pretty universal for Markdown linting.

I linked a VSCode extension ( https://github.com/DavidAnson/markdownlint ), but it's heavily influenced by:

• https://github.com/markdownlint/markdownlint

Other linting tools also uses markdownlint for markdown, like:

• https://github.com/super-linter/super-linter
• https://github.com/oxsecurity/megalinter

I think other tools would use .markdownlint.json too.

---

If you'd like a config to only apply in VSCode, Markdownlint (the extension) configuration can also be added to .vscode/settings.json. Example:

{
  "markdownlint.config": {
    "default": true,
    "MD013": {
      "line_length": 100
    },
    "MD014": false,
    "MD046": false
  }
}

If you have a different way to get feedback from a markdown linter while editing, I'll adapt.

If you don't want .markdownlint.json I'm fine with that too.