Remove legacy Mongoid 3 & 4 docs link

alexbevi · web-flow · commit 5b52d12a3d1d · 2024-02-15T14:41:03.000-05:00
diff --git a/source/index.txt b/source/index.txt
@@ -22,6 +22,3 @@ the `railsmdb <https://github.com/mongodb/mongoid-railsmdb>`_ utility can be use
   contributing
   additional-resources
   ecosystem
-
-
-For documentation on Mongoid 3 and 4, see `<http://mongoid.github.io>`_.
