Update commonmarker requirement from ~> 1.1.2 to ~> 2.0.1

Updates the requirements on [commonmarker](https://github.com/gjtorikian/commonmarker) to permit the latest version.
- [Release notes](https://github.com/gjtorikian/commonmarker/releases)
- [Changelog](https://github.com/gjtorikian/commonmarker/blob/main/CHANGELOG.md)
- [Commits](gjtorikian/commonmarker@v1.1.2...v2.0.1)

---
updated-dependencies:
- dependency-name: commonmarker
  dependency-type: direct:development
...

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

Author: dependabot[bot]

Gemfile

@@ -10,7 +10,7 @@ group :development do
   end
   group :documentation do
     gem 'yard', github: 'ParadoxV5/yard', tag: 'commonmarker-1.0_1', require: false
-    gem 'commonmarker', '~> 1.1.2', require: false
+    gem 'commonmarker', '~> 2.0.1', require: false
   end
   group :test do
     gem 'rake', '~> 13.2.1'