Add commonmarker to related projects

Author: gjtorikian

README.md

@@ -306,18 +306,23 @@ depending on your use-case. Here are some other projects to consider:
 - [markdown-rs](https://github.com/wooorm/markdown-rs) (1.x) looks worth watching.
 - Know of another library? Please open a PR to add it!
 
-### Python bindings
-
-- [comrak (Python package)](https://github.com/lmmx/comrak) — Python bindings for this library built with PyO3.
-  Available on PyPI as [`comrak`](https://pypi.org/project/comrak), benchmarked at 15-60x faster than pure Python alternatives.
+As far as I know, Comrak is the only library to implement all of the [GitHub Flavored Markdown
+extensions](https://github.github.com/gfm) rigorously.
 
 ### Elixir bindings
 
 - [mdex](https://github.com/leandrocp/mdex) - Elixir bindings for this library built with Rustler.
   Available on Hex as [`mdex`](https://hex.pm/packages/mdex).
 
-As far as I know, Comrak is the only library to implement all of the [GitHub Flavored Markdown
-extensions](https://github.github.com/gfm) rigorously.
+### Python bindings
+
+- [comrak (Python package)](https://github.com/lmmx/comrak) — Python bindings for this library built with PyO3.
+  Available on PyPI as [`comrak`](https://pypi.org/project/comrak), benchmarked at 15-60x faster than pure Python alternatives.
+
+### Ruby bindings
+
+- [commonmarker](https://github.com/gjtorikian/commonmarker) - Ruby bindings for this library built with Magnus/rb-sys.
+  Available on RubyGems as [`commonmarker`](https://rubygems.org/gems/commonmarker).
 
 ## Benchmarking