Changed docs link to stable version

This can help avoid potential confusion, like what appears to have been
the cause of #1326.

Author: ddabble

README.rst

@@ -49,7 +49,7 @@ main        3.10, 3.11, 3.12, 3.13-dev
 Getting Help
 ------------
 
-Documentation is available at https://django-simple-history.readthedocs.io/
+Documentation is available at https://django-simple-history.readthedocs.io/en/stable/
 
 Pull requests are welcome.  Read the `CONTRIBUTING`_ file for tips on
 submitting a pull request.

setup.py

@@ -20,7 +20,7 @@
         maintainer="Trey Hunner",
         url="https://github.com/jazzband/django-simple-history",
         project_urls={
-            "Documentation": "https://django-simple-history.readthedocs.io/",
+            "Documentation": "https://django-simple-history.readthedocs.io/en/stable/",
             "Changelog": "https://github.com/jazzband/django-simple-history/blob/master/CHANGES.rst",  # noqa: E501
             "Source": "https://github.com/jazzband/django-simple-history",
             "Tracker": "https://github.com/jazzband/django-simple-history/issues",