fix branch name

Author: aliciaaevans

.github/workflows/jekyll-gh-pages.yml

@@ -43,7 +43,7 @@ jobs:
   deploy:
     environment:
       name: github-pages
-      url: ${{ steps.deployment.outputs.page_url }}/${GITHUB_REF}
+      url: ${{ steps.deployment.outputs.page_url }}/${{ github.head_ref || github.ref_name }} 
     runs-on: ubuntu-latest
     needs: build
     steps: