Setup CI to build the documentation to a Docker image (#208)

* Add Docker deployment

* Remove the manually built version

* Fix the dockerfile

.github/workflows/container-release.yml

@@ -0,0 +1,35 @@
+---
+name: Build and release container
+
+on:
+  push:
+    branches:
+      - "master"
+
+jobs:
+  release:
+
+    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 registry
+        uses: docker/login-action@v1
+        with:
+          registry: quay.io
+          username: ${{ secrets.QUAY_USERNAME }}
+          password: ${{ secrets.QUAY_PASSWORD }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: quay.io/invidious/docs.invidious.io:latest