Update README.md with github.io reference

Author: tim-schilling

README.md

@@ -1,7 +1,9 @@
-# django-commons.github.io
+# Django Commons mkdocs
 
 The Django Commons docs are deployed at [django-commons.org](https://django-commons.org).
 
+The repository that hosts the docs is at https://github.com/django-commons/django-commons.github.io
+
 ## Local Development
 
 1. Create a Python 3.13 virtual environment (`uv venv --python 3.13`)