Add learn-ruby.org to Documentation Resources

Hello Ruby Core Team,

I'd like to suggest adding learn-ruby.org to the documentation resources.

What it is

An interactive platform for learning Ruby 3.4 with hands-on exercises in Test-First Teaching style. Users write code directly in the browser to pass RSpec tests.

Key features

• 61 exercises across 16 lessons (basics → Ruby 3.4 features)
• Covers modern Ruby: it parameter, pattern matching, Data classes
• Browser-based code editor with sandboxed execution
• Immediate feedback with test results
• No installation required
• Free and open source (MIT License)
• Available in English and Russian

Technical details

• Ruby 3.4.4, Rails 8.0.3
• Source: https://github.com/Ruslanux/learn_ruby
• Live: https://learn-ruby.org

Why include it

The platform focuses specifically on modern Ruby 3.4 features and provides a practical, test-driven approach to learning — complementing existing resources like Try Ruby and Ruby Koans.

Happy to provide any additional information or make adjustments.

Thank you for considering!

The issue does not name a file or test; start by locating the website's documentation resources section and reviewing how existing resources are represented. Add learn-ruby.org with the supplied link and an accurate short description, then verify the rendered resources page contains the entry.