Add info on distinct id for identify event

Author: niallzato

src/connections/destinations/catalog/actions-mixpanel/index.md

@@ -107,7 +107,7 @@ The group id that Mixpanel will use is `12345`.
 
 {% capture identify_user_details %}
 > success ""
-> The below special traits will be mapped to Mixpanel reserved properties automatically to fit Mixpanel's use cases. `traits.created` -> `$created`, `traits.email` -> `$email`, `traits.firstName` -> `$first_name`, `traits.lastName` -> `$last_name`, `traits.name` -> `$name`, `traits.username` -> `$username` and `traits.phone` -> `$phone`.
+> The userId set in the identify event will be mapped to the distinct ID in Mixpanel. The below special traits will be mapped to Mixpanel reserved properties automatically to fit Mixpanel's use cases. `traits.created` -> `$created`, `traits.email` -> `$email`, `traits.firstName` -> `$first_name`, `traits.lastName` -> `$last_name`, `traits.name` -> `$name`, `traits.username` -> `$username` and `traits.phone` -> `$phone`.
 
 {% endcapture %}