Add trailing slash to build

Author: beefoo

.github/workflows/deploy.yml

@@ -39,7 +39,7 @@ jobs:
       # Build the book
       - name: Build the book
         run: |
-          jupyter-book build --all .
+          jupyter-book build --all ./
 
       # https://docs.github.com/en/pages/getting-started-with-github-pages/configuring-a-publishing-source-for-your-github-pages-site#publishing-with-a-custom-github-actions-workflow