Added GitHub Actions workflow

.github/workflows/build-image.yml

@@ -0,0 +1,27 @@
+name: Build Docker image
+on:
+  push:
+    branches:
+      - master
+      - Backend
+jobs:
+  push_to_ghcr:
+    name: Push to ghcr.io
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v2
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Publish
+        env: 
+          tags: ${{ format('{0},{1}', format('ghcr.io/{0}:latest', github.repository), format('ghcr.io/{0}:{1}', github.repository, github.ref_name)) }}
+        uses: docker/build-push-action@v2
+        with:
+          context: ./server
+          tags: ${{ env.tags }}
+          push: true