deprecated function show_menu() and menu()

[jacobi22]

Due to an accident while recoding the file "frontend.functions. php" it was forgotten to add the old function show_menu ().
Since this function show_menu () has been deprecated for years (see also here), we decided not to provide this function with a fix.
Help for changing over to the show_menu2 () function can be found here ->
 
 
Show_Menu2 - README + Solutions for different navigations

and here ->

Show_Menu2 - README + Lösungen für verschiedene Menüs

as well as in many articles about show_menu2 ()

Admin edit: removed hint to use alternate functions, because produce a lot of error messages