Add the ability to export/import the game code so it can be edited externally

[drako0812]

You could probably print a message if the imported code is too large, and in that case don't overwrite the current code.

Also, you could probably name the file <cart-name>.lua for simplicity, except that doesn't cover the case of an unsaved new cart.

[nesbox]

There are two methods to edit code in external editor:

• add dofile('game.lua') to the first line and place game.lua near TIC exe
• or use tic cart.tic -code game.lua command line parameters to inject your code to the cartridge (https://github.com/nesbox/tic.computer/wiki#command-line-arguments)

[nesbox]

pls close the issue if this helped you
thanks

[drako0812]

Oh right, thanks! I remember reading about those, I was tired when I opened the issue.