add PR GitHub action

.github/workflows/pr.yml

@@ -0,0 +1,40 @@
+name: Website Checks
+
+on:
+  pull_request:
+    branches:
+      - main
+      - staging
+  push:
+    branches:
+      - main
+      - staging
+
+jobs:
+  lint:
+    name: Check formatting
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Check formatting with Prettier
+        run: npm run lint:prettier
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v3
+        with:
+          node-version: 18
+          cache: npm
+      - name: Install dependencies
+        run: npm ci
+      - name: Build website
+        run: npm run build
+