Run build on PRs

.gitea/workflows/deploy.yml

@@ -4,9 +4,29 @@ on:
   push:
     branches:
       - main
+  pull_request:
   workflow_dispatch:
+
 jobs:
-  build-and-deploy-docs:
+  build-docs:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Configure git credentials
+        run: |
+          git config --global user.name "Gitea Actions"
+          git config --global user.email "actions@gitea.local"
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3"
+      - name: Install mkdocs-material
+        run: pip install mkdocs-material=="9.*"
+      - name: Build documentation
+        run: mkdocs build -s
+
+  deploy-docs:
+    needs: build-docs
+    if: github.event_name == 'push' && github.ref == 'refs/heads/main'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -22,8 +42,6 @@ jobs:
       - name: Build documentation
         run: mkdocs build -s
       - name: Deploy documentation
-        # the default mkdocs build output directory `/site` is gitignored
-        # so it's safe to `git rm -rf .`
         run: |
           git checkout --orphan gitea-pages
           git rm -rf .