tabs vs spaces, d'oh!

Author: kandersolar

Diff for: .github/workflows/build-gh-pages.yaml

@@ -22,7 +22,7 @@ jobs:
     - name: Install dependencies
       run: |
         pip install -r requirements.txt
-		pip install jupyter-book
+        pip install jupyter-book
 
     # Build the book
     - name: Build the book