Bump html-proofer from 3.18.8 to 3.19.0

Bumps [html-proofer](https://github.com/gjtorikian/html-proofer) from 3.18.8 to 3.19.0.
- [Release notes](https://github.com/gjtorikian/html-proofer/releases)
- [Commits](https://github.com/gjtorikian/html-proofer/compare/v3.18.8...v3.19.0)
8 jobs for dependabot/bundler/html-proofer-3.19.0 in 4 minutes and 6 seconds (queued for 2 seconds)