Add job to check GDScript format

.gitattributes

@@ -32,5 +32,6 @@
 /misc export-ignore
 /project.godot export-ignore
 /README.md export-ignore
+/requirements.txt export-ignore
 /test export-ignore
 /themes export-ignore

.github/workflows/main.yml

@@ -311,3 +311,15 @@ jobs:
           exit 1
         fi
 
+  check-code-format:
+    name: 'Check Code Format'
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: 3.x
+    - name: GDFormat Check
+      run: |
+        python -m pip install -r requirements.txt
+        gdformat -c .

requirements.txt

@@ -0,0 +1,4 @@
+docopt==0.6.2
+gdtoolkit==3.3.1
+lark-parser==0.8.0
+PyYAML==6.0