Add build/debug configs

[slembcke]

You mentioned in https://github.com/buserror/mii_emu/blob/main/docs/Compiling.md#development that vscode lacks Make build options. While true, you can make it run any arbitrary command as a default build task (press ctrl-shift-B). I made an example tasks.json file. It has a link to the docs if you want to see more. I also made a launch.json file to build/start the emulator in the debugger (press F5). Though the platform-triple used by the makefile kinda mucks with that as VSCode requires static paths.