Better comments on DOUBLE_CLICK_TIME_WINDOW

Marlin/Configuration_adv.h

  * to the Z-BabyStepping menu.
  */
 //#define DOUBLE_CLICK_JUMPS_TO_Z_BABYSTEPPING
-#define DOUBLE_CLICK_TIME_WINDOW 1250   // How quickly the double click must be done.
+#define DOUBLE_CLICK_TIME_WINDOW 1250   // How quickly the double click must be done in miliseconds.
+                                        // Please notice this time must be a little bit longer than what
+                                        // is actually desired because there is some latency in detecting a
+                                        // change in LCD Panel Button Status.
 
 
 /**