add formatter pipeline

Author: SteffenLm

.github/workflows/format.yaml

@@ -0,0 +1,14 @@
+name: format and commit all java files
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - 'steffen'
+
+jobs:
+  formatting:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: axel-op/googlejavaformat-action@v3