RFC: Add markdown linting for `gh_pages`

[pdelre]

👋 Would the maintainers be interested in PRs to improve the consistency of the markdown in the gh_pages branch for Hacktoberfest? I had worked previously with thephpleague/commonmark to introduce markdownlint Action and take passes on correcting any discovered issues (Change List).

If so, I'd add usage of DavidAnson/markdownlint (JS) as it integrates with VSCode, shell environments, as well as being used by GitHub's Super-Linter Action, further reducing the CI maintenance cost.

I created a small POC of how this would integrate with the gh_pages branch as it's different than thephpleague/commonmark's docs/ directory on main. You can review the results here.

[rosstuck]

Hi, super late reply, but indeed, I'd be interested to have this. :)