Add Black format check workflow

.github/workflows/format-check.yml

@@ -15,4 +15,4 @@ jobs:
           args: .
       - name: Check for modified files
         id: git-check
-        run: echo "modified=$(if git diff-index --quiet HEAD --; then echo "false"; else echo "true"; fi)" >> $GITHUB_OUTPUT
+        run: echo "modified=$(if git diff-index --quiet HEAD --; then echo "Code formatting inconsistent. Please format using Black."; else echo "Code formatting is consistent with Black."; fi)" >> $GITHUB_OUTPUT