Document all FOREACH loops.

src/ScreenEdit.h

@@ -136,6 +136,7 @@ enum EditButton
 	NUM_EditButton, // leave this at the end
 	EditButton_Invalid
 };
+/** @brief A special foreach loop for the different edit buttons. */
 #define FOREACH_EditButton( e ) FOREACH_ENUM( EditButton, e )
 const int NUM_EDIT_TO_DEVICE_SLOTS = 2;
 const int NUM_EDIT_TO_MENU_SLOTS = 2;