feat(send-email): example FROM email

Author: russellwheatley

firestore-send-email/extension.yaml

@@ -109,6 +109,7 @@ params:
     required: true
     description: >-
       The email address to use as the sender's address (if it's not specified in the added email document).
+    example: foobar <foobar@example.com>  
 
   - param: DEFAULT_REPLY_TO
     type: string