Add build script for release.

Thank you very much to @ThoFrank for these patches.

.github/workflows/build_release_container.yml

@@ -0,0 +1,22 @@
+name: Build Release Container
+on:
+  push:
+    tags:
+      - '*'
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build image
+        run: |
+          cd docker
+          docker build -t ghcr.io/coleifer/sqlite-web:${{  github.ref_name }} .
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{github.actor}}
+          password: ${{secrets.GITHUB_TOKEN}}
+      - name: Upload versioned container to registry
+        run: docker push ghcr.io/coleifer/sqlite-web:${{  github.ref_name }}