Add release process documentation

Author: tcdent

RELEASE.md

@@ -0,0 +1,54 @@
+# Release Process
+
+## 1. Bump version
+
+```bash
+# Edit Cargo.toml version
+vim Cargo.toml
+
+git add Cargo.toml Cargo.lock
+git commit -m "Bump version to X.Y.Z"
+git push origin main
+```
+
+## 2. Tag and push
+
+```bash
+git tag vX.Y.Z
+git push origin vX.Y.Z
+```
+
+This triggers the [Release workflow](https://github.com/tcdent/codey/actions/workflows/release.yml) which builds for:
+- `codey-darwin-arm64` (macOS ARM)
+- `codey-linux-x86_64` (Linux x86)
+- `codey-linux-arm64` (Linux ARM)
+
+## 3. Update Homebrew tap
+
+Once the release workflow completes, get SHA256 hashes:
+
+```bash
+VERSION=X.Y.Z
+curl -sL https://github.com/tcdent/codey/releases/download/v$VERSION/codey-darwin-arm64.tar.gz | shasum -a 256
+curl -sL https://github.com/tcdent/codey/releases/download/v$VERSION/codey-linux-x86_64.tar.gz | shasum -a 256
+curl -sL https://github.com/tcdent/codey/releases/download/v$VERSION/codey-linux-arm64.tar.gz | shasum -a 256
+```
+
+Update `~/Work/tap/Formula/codey.rb`:
+- `version "X.Y.Z"`
+- SHA256 hashes for each platform
+
+```bash
+cd ~/Work/tap
+git add -A
+git commit -m "Update codey to vX.Y.Z"
+git push
+```
+
+## Version scheme
+
+```
+0.1.0-alpha.1   # Early development
+0.1.0-rc.1      # Release candidate
+0.1.0           # Stable release
+```