Updates to docs.yaml (#6)

* Updates to docs.yaml from https://github.com/mozilla-ai/document-to-podcast

* Add paths

.github/workflows/docs.yaml

@@ -3,6 +3,15 @@ name: Documentation
 on:
   push:
     branches: [main]
+    paths:
+      - mkdocs.yml
+      - 'docs/**'
+      - 'src/**'
+  pull_request:
+    paths:
+      - mkdocs.yml
+      - 'docs/**'
+      - 'src/**'
   workflow_dispatch:
 
 jobs:
@@ -20,15 +29,20 @@ jobs:
         uses: actions/setup-python@v5
         with:
           python-version: '3.10'
+          cache: "pip"
 
       - name: Configure git
         run: |
           git config user.name 'github-actions[bot]'
           git config user.email 'github-actions[bot]@users.noreply.github.com'
 
       - name: Install requirements
-        run: pip install -r docs/requirements.txt
+        run: pip install -e '.[docs]'
 
-      - name: Publish docs
+      - name: Build docs
+        if: github.event_name == 'pull_request'
+        run: mkdocs build -s
 
+      - name: Publish docs
+        if: ${{ github.event_name == 'push' || github.event_name == 'workflow_dispatch' }}
         run: mkdocs gh-deploy