Link to GA documentation for required parameters

Author: jfoskin

src/_includes/components/actions-fields.html

@@ -83,6 +83,9 @@
 ## Available Actions
 
 Build your own Mappings! Combine supported [triggers](/docs/connections/destinations/actions/#components-of-a-destination-action) with the following {{currentIntegration.display_name | remove: " (Actions)"}}-supported actions:
+> warning ""
+> Please refer to the [Google Analtyics](https://developers.google.com/analytics/devguides/collection/ga4/reference/events?client_type=gtag#purchase) documentation for the list of required fields, 
+We want to ensure you have the most up-to-date information, as the required fields may change.
 
 <div class="premonition info">
   <div class="fa fa-info-circle"></div>