elyra-ai#2088 Title info doc updates

Signed-off-by: Carita Ou <[email protected]>

docs/pages/04.03-ui-hints.md

@@ -291,6 +291,23 @@ Example complex_type_info section:
     }
  ]
 ```
+
+## Title-info
+The title_info sections defines what will be displayed in the title section alongside the `titleDefinition`.
+
+Title info attributes.
+
+* `action_refs` (*array[string]*) List of action to be displayed in the title section. Each action_ref must have a corresponding action defined in the action_info section.
+
+Example title info section:
+```js
+"title_info": {
+   "action_refs": [
+      "increment"
+   ]
+}
+```
+
 ## Action Info
 The action_info section defines an action.  Actions are used to callback to the application to perform an operation.