Extract contributing guideline into a CONTRIBUTING.md

CONTRIBUTING.md

@@ -0,0 +1,52 @@
+# Contributing to IRB
+
+Bug reports and pull requests are welcome on GitHub at [https://github.com/ruby/irb](https://github.com/ruby/irb).
+
+## Set up the environment
+
+1. Fork the project to your GitHub account
+2. Clone the fork with `git clone [email protected]:[your_username]/irb.git`
+3. Run `bundle install`
+4. Run `bundle exec rake` to make sure tests pass locally
+
+### Run integration tests
+
+If your changes affect component rendering, such as the autocompletion's dialog/dropdown, you may need to run IRB's integration tests, known as `yamatanooroti`.
+
+Before running these tests, ensure that you have `libvterm` installed. If you're using Homebrew, you can install it by running:
+
+```bash
+brew install libvterm
+```
+
+After installing `libvterm`, you can run the integration tests using the following commands:
+
+```bash
+WITH_VTERM=1 bundle install
+WITH_VTERM=1 bundle exec rake test test_yamatanooroti
+```
+
+### Update documentation
+
+IRB's documentation is generated by [RDoc](https://ruby.github.io/rdoc/) and published to [ruby.github.io/irb](https://ruby.github.io/irb/). Most of the documentation source lives under the `doc/` directory.
+
+Run the following command to generate the documentation site locally.
+
+```bash
+bundle exec rake rdoc
+bundle exec rake rerdoc # to force regeneration
+```
+
+Follow the output message to open the documentation site in your browser.
+
+> [!Note]
+>
+> Please ensure that the changes are rendered correctly on the documentation site.
+> RDoc's Markdown support is limited, so the rendered result on GitHub might differ from what’s rendered on [https://ruby.github.io/irb](https://ruby.github.io/irb).
+
+We welcome any improvements to the documentation, including:
+
+- Fixing typos and grammatical errors
+- Adding missing documentation for features
+- Adding missing documentation for configuration options
+- Adding demo images/gifs for features

README.md

@@ -117,31 +117,7 @@ To install this gem onto your local machine, run `bundle exec rake install`. To
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/irb.
-
-### Set up the environment
-
-1. Fork the project to your GithHub account
-2. Clone the fork with `git clone [email protected]:[your_username]/irb.git`
-3. Run `bundle install`
-4. Run `bundle exec rake` to make sure tests pass locally
-
-### Run integration tests
-
-If your changes affect component rendering, such as the autocompletion's dialog/dropdown, you may need to run IRB's integration tests, known as `yamatanooroti`.
-
-Before running these tests, ensure that you have `libvterm` installed. If you're using Homebrew, you can install it by running:
-
-```bash
-brew install libvterm
-```
-
-After installing `libvterm`, you can run the integration tests using the following commands:
-
-```bash
-WITH_VTERM=1 bundle install
-WITH_VTERM=1 bundle exec rake test test_yamatanooroti
-```
+See [CONTRIBUTING.md](./CONTRIBUTING.md) for more information.
 
 ## Releasing
 

doc/Index.md

@@ -687,6 +687,10 @@ Command-line option `-E *ex*[:*in*]` sets initial external (ex) and internal (in
 
 Command-line option `-U` sets both to UTF-8.
 
+## Contributing
+
+See [CONTRIBUTING.md](https://github.com/ruby/irb/blob/main/CONTRIBUTING.md) for more information.
+
 ## Extending \IRB
 
 \IRB `v1.13.0` and later versions allow users/libraries to extend its functionality through official APIs.