Add build workflow

.github/workflows/build-and-push.yaml

@@ -0,0 +1,38 @@
+name: Build and Push Docker images
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up Docker Builder
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push API image
+        uses: docker/build-push-action@v2
+        with:
+          context: ./api
+          push: true
+          tags: ghcr.io/r-dvl/${{ github.repository }}/bandanize-api:latest
+
+      - name: Build and push UI image
+        uses: docker/build-push-action@v2
+        with:
+          context: ./ui
+          push: true
+          tags: ghcr.io/r-dvl/${{ github.repository }}/bandanize-ui:latest