feat: add GitHub release description update via --release flag

### CHANGES

- Add `--release` flag to generate_changelog to update GitHub release
- Implement `ReleaseManager` for managing release descriptions
- Create `release.go` for handling release updates
- Update `release.yml` to run changelog generation
- Ensure mutual exclusivity for `--release` with other flags
- Modify `Config` struct to include `Release` field
- Update `main.go` to handle new release functionality

.github/workflows/release.yml

@@ -122,6 +122,7 @@ jobs:
           else
             echo "Release ${{ env.latest_tag }} already exists."
           fi
+          go run ./cmd/generate_changelog --release ${{ env.latest_tag }}
 
       - name: Upload release artifact
         if: matrix.os == 'windows-latest'