Add Ruby.

While he doesn't really contribute code to Ruby itself anymore, the language founder is a proponent of programming with LLMs. He does so in the language spin-off mruby quite heavily.
Ruby itself contains commits co-authored by Claude, contributed by a core maintainer.
TruffleRuby, an alternative language implementation, contains code by Copilot, contributed by the project lead.
JRuby is not listed as an alternative because, while its lead is a vocal critic of LLMs for code generation, he appears open to it still and has also posted about using them for things (that might not be JRuby, tbf).

README.md

@@ -202,6 +202,7 @@ To Contribute, checkout our [`CONTRIBUTING.md`](./CONTRIBUTING.md).
 | [`.NET`](https://dotnet.microsoft.com/) | See below | [`.NET Runtime` PRs](https://github.com/dotnet/runtime/pulls?q=author%3A%40copilot+is%3Amerged), [`.NET SDK` PRs](https://github.com/dotnet/sdk/pulls?q=author%3A%40copilot+is%3Amerged) |
 | [Julia](https://julialang.org/) | An older version of Python (w/ appropriate scientific libraries) | [`AGENTS.md` in main repository](https://github.com/JuliaLang/julia/pull/58561), [PRs "written by Claude"](https://github.com/JuliaLang/julia/pulls?q=is%3Apr+written+by+Claude) | |
 | [Python](https://python.org) | Older version of Python; [Lua] | [Contains code from Claude](./evidence/img/cpython-claude.png) | |
+| [Ruby](https://www.ruby-lang.org) | | [Maintainer contributed code from Claude](https://github.com/ruby/ruby/commit/a0fc03ef3717ad0aab363a53a6f6f178dab7b526) ([Screenshot](./evidence/img/ruby.png)) | mruby (spin-off) [vibe coded by language founder](https://github.com/mruby/mruby/commit/b9a1a1fb2389e5b36dd0f0d9a6f95818f7f30af5) ([Screenshot](./evidence/img/mruby.png)); TruffleRuby (alternative implementation) [contains code from Claude, contributed by lead maintainer](https://github.com/truffleruby/truffleruby/commit/9f028ec178642bc71285a32c82b0a2761723b40b) |
 | [Typescript](https://www.typescriptlang.org/) | Normal JavaScript; [Lua] | Contains [Copilot instructions](https://github.com/microsoft/TypeScript/blob/main/.github/copilot-instructions.md) and multiple commits from Copilot (e.g. [1](https://github.com/microsoft/TypeScript/commit/c9e7428bb76f0543a3555d0af87777e7db3a41e6), [2](https://github.com/microsoft/TypeScript/commit/ad04bf7488384a5dcdf7d250ccb8e5263021a8ff), [3](https://github.com/microsoft/TypeScript/commit/66edca11c98ade9a5e2a2b019fdad7d58ee9d4ac), [4](https://github.com/microsoft/TypeScript/commit/7f6a84673def7665a4c4bc2bdfaf7bcc8549b276)) | |
 
 > [!Note]