Added build script and configs

Created by: midwan

Added the following:

• Build command script for Windows (contains comments to indicate what to adjust, if necessary)
• VSCode config for Build and Clean commands, under Windows, MacOS, Linux.
• VSCode config for C/C++ Intellisense (the paths are Windows-specific for now, but can easily be adjusted)

These hopefully make things easier when editing the code in VSCode, and allow you to Build (and Clean) very easily from within there:

• Press F1, select "Tasks: Run Task" and then select either "Build" or "Clean"

PS: We could also add the "Pack" option to LHA the resulting binary as an extra command.