First attempt to build on pull requests

.github/workflows/preview.yml

@@ -0,0 +1,43 @@
+# .github/workflows/preview.yml
+name: Deploy PR previews
+
+env:
+  ZOLA_VERSION: "0.17.2"
+  # MAIN_BRANCH: "main"
+  # TARGET_BRANCH: "gh-pages"
+  # CNAME: "hpc.uit.no"
+on:
+  pull_request:
+    types:
+      - opened
+      - reopened
+      - synchronize
+      - closed
+
+concurrency: preview-${{ github.ref }}
+
+jobs:
+  deploy-preview:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Checkout repository and submodules
+        uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - name: Install zola
+        run: |
+          set -x
+          wget -O - \
+             "https://github.com/getzola/zola/releases/download/v${ZOLA_VERSION}/zola-v${ZOLA_VERSION}-x86_64-unknown-linux-gnu.tar.gz" \
+          | sudo tar xzf - -C /usr/local/bin
+      - name: Generate HTML
+        run: zola build
+        # Add CNAME, either (first one used)
+        # - file in the root
+        # - the environment variable set above
+      - name: Deploy preview
+        uses: rossjrw/pr-preview-action@v1
+        with:
+          source-dir: ./public