Update yaml2json.yml

Author: cebe

.github/workflows/yaml2json.yml

@@ -44,7 +44,9 @@ jobs:
         rm -rf vendor/ composer.*
 
     - name: git diff
-      run: git diff
+      run: |
+        git add *.json
+        git diff --staged
 
     - name: Create Pull Request
       uses: peter-evans/create-pull-request@v1