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](gjtorikian/commonmarker@v0.23.4...v0.23.6)

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

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

Author: dependabot[bot]

docs/Gemfile.lock

@@ -4,7 +4,7 @@ GEM
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
     colorator (1.1.0)
-    commonmarker (0.23.4)
+    commonmarker (0.23.6)
     concurrent-ruby (1.1.10)
     em-websocket (0.5.3)
       eventmachine (>= 0.12.9)