Bump ex_doc from 0.22.5 to 0.22.6
Bump ex_doc from 0.22.5 to 0.22.6

Bumps [ex_doc](https://github.com/elixir-lang/ex_doc) from 0.22.5 to 0.22.6.
- [Release notes](https://github.com/elixir-lang/ex_doc/releases)
- [Changelog](https://github.com/elixir-lang/ex_doc/blob/master/CHANGELOG.md)
- [Commits](https://github.com/elixir-lang/ex_doc/compare/v0.22.5...v0.22.6)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
asaaki/cmark.ex,asaaki/cmark.ex