added admonition to ticket/search api page mentioning the correct categories to use when searching for a ticket

Author: MarkHarrison03

descriptions/0/api.intercom.io.yaml

@@ -12929,6 +12929,12 @@ paths:
         | snoozed_until                             | Date (UNIX timestamp)                                                                    |
         | ticket_attribute.{id}                     | String or Boolean or Date (UNIX timestamp) or Float or Integer                           |
 
+        {% admonition type="info" name="Searching by Category" %}
+        When searching for tickets by the **`category`** field, specific terms must be used instead of the category names:
+        * For **Customer** category tickets, use the term `request`.
+        * For **Back-office** category tickets, use the term `task`.
+        * For **Tracker** category tickets, use the term `tracker`.
+
         ### Accepted Operators
 
         {% admonition type="info" name="Searching based on `created_at`" %}