add ci docker build

.forgejo/workflows/docker-build.yml

@@ -0,0 +1,20 @@
+name: ci
+
+on:
+  push:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Login to Local Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: forgejo.ultrablob.me
+          username: ${{ env.GITHUB_ACTOR }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build and push
+        uses: docker/build-push-action@v6
+        with:
+          push: true
+          tags: ultrablob/ape-ame-backend:latest