(DOCSP-6409) clarifying verified signature description

Author: jeff-allen-mongo

source/manage-data-sources.txt

@@ -59,7 +59,7 @@ embedding for a data source:
 #. Select either:
 
    a. :guilabel:`Verified Signature only`. This option requires
-      embedded charts to include a :ref:`secret embedding key
+      embedded charts to include a :ref:`verified signature
       <embedding-charts>` with each request sent to the data source.
       Without a verified signature, the chart will not render. This
       option allows the chart owner to ensure that the chart is used