chore: update Swift version to 6.1 and add improvement checklist documentation

Author: zamderax

.github/workflows/swift.yml

@@ -33,7 +33,7 @@ jobs:
     - name: Setup Swift
       uses: swift-actions/setup-swift@v2
       with:
-        swift-version: '6.0'
+        swift-version: '6.1'
 
     - name: Build
       run: swift build -v