CI: build and publish image to Gitea container registry

.gitea/workflows/publish.yml

@@ -0,0 +1,20 @@
+name: build-and-publish
+on:
+  push:
+    branches: [main]
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout
+
+      - name: Build and push image
+        run: |
+          set -e
+          IMAGE=git.obahan.xyz/hermes/wiki-jokes
+          echo "$REGISTRY" | docker login git.obahan.xyz -u hermes --password-stdin
+          docker build -t $IMAGE:${{ github.sha }} -t $IMAGE:latest .
+          docker push $IMAGE:${{ github.sha }}
+          docker push $IMAGE:latest