Bump commonmarker from 0.23.4 to 0.23.6 in /docs

Bumps [commonmarker](https://github.com/gjtorikian/commonmarker) from 0.23.4 to 0.23.6.
- [Release notes](https://github.com/gjtorikian/commonmarker/releases)
- [Changelog](https://github.com/gjtorikian/commonmarker/blob/main/CHANGELOG.md)
- [Commits](https://github.com/gjtorikian/commonmarker/compare/v0.23.4...v0.23.6

)

---
updated-dependencies:
- dependency-name: commonmarker
  dependency-type: indirect
...

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

docs/Gemfile.lock

@@ -14,7 +14,7 @@ GEM
       execjs
     coffee-script-source (1.11.1)
     colorator (1.1.0)
-    commonmarker (0.23.4)
+    commonmarker (0.23.6)
     concurrent-ruby (1.1.10)
     dnsruby (1.61.9)
       simpleidn (~> 0.1)