Add documentation headers across system modules

Trenser.VehicleServiceSystem/Trenser.VehicleServiceSystem/views/CustomerMenu.cpp

@@ -55,6 +55,15 @@ void CustomerMenu::selectComboPackage()
 {
 }
 
+/*
+Function: viewServiceHistory
+Description: Displays the customer’s past service bookings in tabular format,
+             including booking ID, technician, vehicle details, discount percentage, and status.
+Parameters:
+    - None
+Returns:
+    - void
+*/
 void CustomerMenu::viewServiceHistory()
 {
 	util::clear();