Some additional information for TECH.md

[sagamusix]

Nice effort and nice write-up! Here's some additional information on the stuff you have written in TECH.md: DOSBox can display the menu just fine, but you have to force it to emulate a VGA-only machine by setting machine=vgaonly. It's not quite clear why DOSBox does not emulate this properly in the default SVGA mode, because the game runs just fine on SVGA cards - I suspect that emulation is faster that way for all other games that don't need this feature.