add workflow

.gitea/workflows/build_push.yml

@@ -0,0 +1,32 @@
+name: Build and Publish Docker Image
+
+on:
+  push:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Show environment variables
+        run: |
+          set
+
+      - name: Login to Docker Registry
+        uses: docker/login-action@v3
+        with:
+          registry: gitea.psi.ch
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: gitea.psi.ch/${{ github.repository }}:latest