Add menu for selecting the level font

By default, when you open the level editor to start a new level, the
level font will now match your VVVVVV language; so if you're, say,
Japanese, then you can make Japanese levels from the get-go. If you
want to make levels for a different target audience, you can change the
font via a new menu (map settings > change description > change font).
The game will remember this choice and it will become the new initial
level font.

desktop_version/src/Game.h

@@ -53,6 +53,7 @@ namespace Menu
         ed_desc,
         ed_music,
         ed_quit,
+        ed_font,
         options,
         gameplayoptions,
         speedrunneroptions,