Add doc deployment job

Author: dstansby

.github/workflows/docs.yml

@@ -6,7 +6,7 @@ on:
       - main
 
 jobs:
-  build-and-upload:
+  build-docs:
     name: Build & Upload Artifact
     runs-on: ubuntu-latest
     steps:
@@ -33,3 +33,19 @@ jobs:
         with:
           name: docs
           path: docs/_build
+
+  upload-docs:
+    name: Upload docs to GitHub pages
+    runs-on: ubuntu-latest
+    needs: build-docs
+    steps:
+    - uses: actions/download-artifact@v3
+      with:
+        name: docs
+
+    - name: Push to GitHub pages
+      uses: peaceiris/actions-gh-pages@v3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: ./docs/_build/html
+        destination_dir: dev