dd58c1ff

By: Michael Lynch <git@mtlynch.io>

Fix pre-existing Prettier and ESLint failures

- Format dev-scripts/serve-design-doc and
  handlers/templates/pages/about.html with Prettier.
- Add reference/ to ESLint ignore list so third-party vendored
  JS in the reference directory does not trigger lint errors.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>