DOCS-16635 Fix Incorrect convertToCapped Sharding Statement (#6564) (#6597)

* DOCS-16635 Fix Incorrect convertToCapped Sharding Statement

* warning title

Author: ajhuh-mdb

source/reference/command/convertToCapped.txt

@@ -12,11 +12,11 @@ convertToCapped
 
 .. dbcommand:: convertToCapped
 
-   .. warning:: Do Not Run This Command In Sharded Clusters
+   .. warning:: Do Not Run This Command On Sharded Collections
 
 
       MongoDB does **not** support the :dbcommand:`convertToCapped`
-      command in a sharded cluster.
+      command on sharded collections.
 
    The :dbcommand:`convertToCapped` command converts an existing,
    non-capped collection to a :term:`capped collection` within the same