Update Engage Section.md

The Engage section in the Kustomer docs needs to be updated or remove to reflect the current functionality for this integration.

Left a note on lines 82-84 with the details. The details should NOT be published in the public docs.

Author: MStephen024

src/connections/destinations/catalog/kustomer/index.md

@@ -78,3 +78,7 @@ analytics.track("Registered", {
 ```
 
 Track calls will sent as a `tracking event` to Kustomer on the timeline of the customer who was tracked. If the `kustomer_session_id` is included, it will cluster this tracking event into a single "session" on the customer's timeline. If no `kustomer_session_id` is supplied, we will automatically generate session IDs based on time between tracking events. (Read why Segment doesn't have session tracking [here](https://segment.com/blog/facts-vs-stories-why-segment-has-no-sessions-api/)).
+
+[**ALERT:** ENGAGE SECTION IS NOT ACCURATE FOR THIS DESTINATION]
+
+This integration is maintained by Kustomer and they only accept standard properties (name, email, phone, etc.), not custom properties (e.g. my_computed_trait_name). Since, any Audience/Computed Trait created in Engage and sent to Kustomer would automatically be considered a custom property, Engage technically does not function properly with Kustomer.