Remove ability to create menus inside config.yml

[BlitzOffline]

Remove ability to create menus inside config.yml. With version 1.14.0 of DeluxeMenus we've deprecated that option so we need to start thinking about removing it entirely.

I think the best way to do this is completely ignore menus declared inside config.yml that do not have a file: specified and throw a big red warning in console.

Some people that do not read the console logs will come complaining but I think it is better than just stopping DeluxeMenus if it finds a menu inside the config.