build(deps-dev): bump tailwindcss from 2.2.4 to 2.2.19 in /docs

Bumps [tailwindcss](https://github.com/tailwindlabs/tailwindcss) from 2.2.4 to 2.2.19.
- [Release notes](https://github.com/tailwindlabs/tailwindcss/releases)
- [Changelog](https://github.com/tailwindlabs/tailwindcss/blob/master/CHANGELOG.md)
- [Commits](tailwindlabs/tailwindcss@v2.2.4...v2.2.19)

---
updated-dependencies:
- dependency-name: tailwindcss
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]