Add github action that builds docker images and pushes them to docker hub

Change-Id: I60d39cc266c2e8b905e2ac4a367bd5a22b79b57b

.github/workflows/docker-release.yml

@@ -0,0 +1,36 @@
+name: Create docker image(s) and push to docker hub
+
+on:
+  push:
+    tags:
+      - '[0-9]+\.[0-9]+\.[0-9]+'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: awesometechnologies/synapse-admin:latest
+      - name: Update repo description
+        uses: peter-evans/dockerhub-description@v2
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+          repository: awesometechnologies/synapse-admin