update workflow triggering

- only on main and when changes happen in docs folder

Author: tobiasehlert

.github/workflows/github-pages.yml

@@ -2,7 +2,10 @@ name: GitHub Pages deployment
 
 on:
   push:
-    branches: [main]
+    branches:
+      - "main"
+    paths:
+      - "docs/**"
   workflow_dispatch:
 
 # Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages