Add PR workflow

.github/workflows/build.yml

@@ -1,6 +1,9 @@
 name: Lint & build
 
-on: [pull_request]
+on:
+  push:
+    branches:
+      - main
 
 jobs:
     build:

.github/workflows/pr.yml

@@ -0,0 +1,70 @@
+name: PR Workflow
+
+on:
+  pull_request:
+    types: [opened, synchronize, ready_for_review, edited, closed]
+    branches:
+      - main
+
+jobs:
+  build:
+    name: Build & lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions/setup-node@v2
+        with:
+          node-version: '16'
+
+      - name: Install dependencies
+        uses: bahmutov/npm-install@v1
+
+      - name: Run lint
+        run: yarn lint
+
+      - name: Build
+        run: yarn build
+
+  release:
+    name: Release snapshot
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      - name: Cache Docker layers
+        uses: actions/cache@v2
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          tags: codetheweb/muse:${{ github.event.pull_request.head.sha }}
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache,mode=max
+
+      - name: Create comment
+        uses: marocchino/sticky-pull-request-comment@v2
+        with:
+          header: "pr-release"
+          message: |
+            #### :package: A new release has been made for this pull request
+
+            To play around with this PR, pull `codetheweb/muse:${{ github.event.pull_request.head.sha }}`.
+
+            > Latest commit: ${{ github.event.pull_request.head.sha }}