Custom command for Execute Document

[Lychrell]

Instead of using the default program used by the File Explorer, it would be better to allow the program to use a different command to run when Execute Document is pressed. I could set it to open my code in the compiler, but I won't be able to add command-line arguments or set environment variables. It would also be neat if there are commands in Notepad3 provided by default.

[ZhianLin]

This can be handy if you have several local python environments, especially if you have python3 and python2 at the same time.