[add] a note on using the subRow config to the subRowConfig property page

Author: mafanya23

docs/grid/api/grid_subrowconfig_config.md

@@ -12,6 +12,10 @@ This functionality requires PRO version of the DHTMLX Grid (or DHTMLX Suite) pac
 
 @short: Optional. Specifies the configuration settings of a sub-row
 
+:::note
+Note that when the [`subRow`](/grid/api/grid_subrow_config/) config is used, Grid doesn't support the [TreeGrid mode](grid/treegrid_mode.md) and the [data grouping](grid/usage.md#grouping-data) functionality.
+:::
+
 @signature: {'subRowConfig?: ((row: IRow) => ISubRowConfig) | ISubRowConfig;'}
 
 @descr: