Add dockerfile and build action

.github/workflows/build.yml

@@ -0,0 +1,31 @@
+name: Build
+
+on:
+  push:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        lfs: true
+
+    - uses: docker/setup-buildx-action@v1
+
+    - name: Login to Docker Hub
+      uses: docker/login-action@v3
+      with:
+        registry: code.smartyellow.net
+        username: ${{ github.actor }}
+        password: ${{ secrets.PACKAGE_TOKEN }}
+
+    - name: Build
+      run: |
+        docker build . -t code.smartyellow.net/romein/hpg-site
+
+    - name: Push
+      run: |
+        docker push code.smartyellow.net/romein/hpg-site