Add paragraph about when to create custom event

Author: sarahrudy

src/connections/destinations/catalog/actions-google-analytics-4-web/index.md

@@ -37,6 +37,8 @@ With custom parameters, you must create [custom dimensions and metrics](https://
 
 ### Custom Events
 
+Before you create a custom event, make sure the event you want to create isn't already collected through an [automatically collected event](https://support.google.com/analytics/answer/9234069?sjid=7831609405656395105-NA){:target="_blank"} or recommended as a [recommended event](https://support.google.com/analytics/answer/9267735?sjid=7831609405656395105-NA){:target="_blank"}. It's always better to use an existing event because these events automatically populate dimensions and metrics that are used in your reports.
+
 Google Analytics 4 does not accept custom event names that include spaces. Segment replaces spaces in the Event Name in the Custom Event action with an underscore. As a result, you will see custom events snake cased in Google Analytics 4.
 
 Event names are case-sensitive in Google Analytics 4. If you would like all event names to be lowercase, use the **Lowercase Event Name** setting when you create a Custom Event mapping and select `Yes` from the dropdown. If this setting is disabled, Google will treat event names with different casing as distinct events.