build(deps-dev): bump github-pages from 204 to 206 in /docs

Bumps [github-pages](https://github.com/github/pages-gem) from 204 to 206.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](https://github.com/github/pages-gem/compare/v204...v206)

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