DOCSP-44217 legacy documentation description (#224)

* DOCSP-44217 legacy documentation description

* DOCSP-44217 legacy documentation description

Author: ltran-mdb2

source/legacy.txt

@@ -7,10 +7,15 @@
 Legacy Documentation
 ====================
 
-MongoDB encourages upgrading to the most recent version to ensure 
-documentation support. If upgrading is not possible, archived 
-documentation is still available for previous versions. Archived 
-documentation no longer receives updates.  
+MongoDB recommends that you upgrade products to the most recent version
+so that you can use the most up-to-date documentation. MongoDB documents
+supported product versions through `MongoDB Documentation
+<https://www.mongodb.com/docs/>`__.
+
+If you cannot upgrade to a supported version, MongoDB provides legacy
+documentation for versions that have reached their end-of-life and are
+no longer recommended for use. MongoDB does not maintain or update
+legacy documentation. 
 
 -----------