Add documentation style guide and tool configs

[danbarr]

Summary

This PR proposes a documentation style guide and configurations for Prettier, markdownlint, and ESLint tooling. The style guide is a subset of Google's documentation and Markdown style guides.

If accepted, I will follow up with another PR to format/lint all of the current docs files.

A final step will be to propose automated checks by way of GitHub workflows to validate formatting on PRs that modify docs.

Change Type

Mark the type of change your PR introduces:

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

Tested that the prettier, markdownlint, and eslint configurations are reporting issues as expected. Auto-generated docs (API/CLI/protocol) have been excluded/ignored.

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• (N/A) Included tests that validate the fix or feature.
• (N/A) Checked that related changes are merged.

[coveralls]

coverage: 56.635% (-0.003%) from 56.638%
when pulling 4253214 on danbarr:docs/add-style-configs
into 19c31fe on mindersec:main.

[evankanderson]

I always use *, but this dog can learn new tricks!

[danbarr]

I used to also; the rationale I drew this from was that it's easier to read when you do things like this:

* **A bold bullet**

vs.

- **A bold bullet**

But frankly, this is a nit - if * are more comfortable/natural I'm not opposed to changing this - consistency is more important than which character.

Markdownlint also support a sublist style which uses different symbols as you nest:

* Item 1
  + Item 2
    - Item 3
  + Item 4
* Item 4
  + Item 5