Updated GitHub Pages documentation (#3207)

* Source branch for GitHub Pages has to be set

Using your awesome workflow, a branch gh-pages is being created, which serves as GitHub Pages source. This has to be set once in the repository settings.

* Source branch for GitHub Pages might have to be set

Author: SchulteDev

docs/publishing-your-site.md

@@ -91,6 +91,10 @@ Now, when a new commit is pushed to either the `master` or `main` branches,
 the static site is automatically built and deployed. Push your changes to see
 the workflow in action.
 
+If the GitHub Page doesn't show up after a few minutes, ensure the source branch
+for your GitHub Page is set to `gh-pages` in your repository settings 
+`github.com/<username>/<repository>/settings/pages`.
+
 Your documentation should shortly appear at `<username>.github.io/<repository>`.
 
   [GitHub Actions]: https://github.com/features/actions