Automated style checks via commit hooks

It would be awesome to have automated style checks (in commit hooks? via GitHub actions on pull requests?) that prevent contributors from committing files that don't adhere to the `web-lower-case` style, and possibly other style conventions for this site.

No files or tests are named. Start by reviewing the repository's existing style conventions and deciding whether commit hooks or GitHub Actions best fits; done means automated checks prevent nonconforming files and the supported conventions are documented.

Written by the indexing model from the issue text.