backup: add action.yml skeleton

.gitea/workflows/build.yml

@@ -18,7 +18,7 @@ jobs:
         - /var/run/docker.sock:/var/run/docker.sock
     steps:
       - uses: actions/checkout@v7
-      - uses: docker/login-action@v4
+      - uses: docker/login-action@v3
         with:
           registry: git.studiovita.li
           username: ${{ secrets.REGISTRY_USERNAME }}

backup/action.yml

@@ -0,0 +1,13 @@
+name: backup
+description: backup all postgres databases
+
+runs:
+  using: "composite"
+  steps:
+    - name: dump databases
+      shell: bash
+      run: |
+        docker ps
+
+    # - name: backup databases
+    #   run: |