Update datatransfer.md

I added !!! attention for the first "prerequisites" note because it was fairly easy to miss. The other 3 additions of "prerequisites" are part of process steps so they are much more easily seen by the reader.

Author: cockerilltim

user-guide/managingdata/datatransfer.md

@@ -10,7 +10,8 @@ This document provides a brief description of the various methods available for
 
 ## Recommended Data Transfer Methods { #recommended }
 
-A prerequiite to using these Data Transfer Methods is to have completed the Getting Started steps of [User Account Registration](/user-guide/#user-account-registration){target="_blank"} and [Initial Onboarding](/user-guide/#initial-onboarding){target="_blank"}.
+!!! attention
+    A prerequisite to using these Data Transfer Methods is to have completed the Getting Started steps of [User Account Registration](/user-guide/#user-account-registration){target="_blank"} and [Initial Onboarding](/user-guide/#initial-onboarding){target="_blank"}.
 
 ### Recommended LARGE Data Transfer Methods { #recommended-largedatatransfer }