docs: add release guide

CONTRIBUTING.md

@@ -0,0 +1,55 @@
+# Contributing
+
+This project is maintained by @luqven. If you have any questions or suggestions, please open an issue or a pull request.
+
+# Release
+
+To release a new version of the project, you need to:
+
+1. Update the version number in the `Cargo.toml` file
+   ```toml
+    [package]
+    version = "0.1.0" // <-- Update this to next version
+    // ...
+   ```
+2. Create a release commit with the changes and tag it with the new version number
+   ```bash
+   git commit -m "chore: release v0.1.0" && git tag v0.1.0
+   ```
+3. Push the commit and tag to the remote repository
+   ```bash
+   git push origin master && git push origin master --tags
+   ```
+4. Create `target/release/` folder with the binary
+   ```bash
+   cargo build --release
+   ```
+5. Create a `.tar.gz` archive of the release bundle that's compatible with Brew and GitHub Releases.
+   ```bash
+   cd target/release
+   tar -czf gh-stack-mac.tar.gz gh-stack
+   ```
+6. Upload the release bundle to the `luqven/gh-stack` repository on GitHub Releases.
+
+   Navigate to the Releases section and then click on "Create a new release".
+   Insert a tag version, IE `v0.1.0`, a title, and then drag the previously created `.tar.gz` archive into the upload section. Click on the `Publish release` button.
+
+7. Copy the sha256sum of the archive to the `homebrew-gh-stack/Formula/gh-stack.rb` file and update the version number.
+
+   ```bash
+   cd target/release
+   shasum -a 256 gh-stack-mac.tar.gz
+   ```
+
+   ```ruby
+   # homebrew-gh-stack repository
+   # /Formula/gh-stack.rb
+   class GhStack < Formula
+      desc "Cross-platform Text Expander written in Rust"
+      homepage "https://github.com/luqven/gh-stack"
+      version "0.1.0"
+      url "https://github.com/luqven/gh-stack/releases/download/#{version}/gh-stack-mac.tar.gz"
+      sha256 "<copied_sha>"
+      ...
+   end
+   ```