Add Linux installation guide

[LittleWhole]

Added a Linux installation guide for people who want to install Minecraft Note Block Studio on Linux. Feel free to move this installation guide anywhere if you don't want it to be in README.

This installation guide was written with my installation of Open NBS on Ubuntu 20.04 LTS

Importance of this pull request:

Just directly WINEing the .exe file will not work on all distros. PulseAudio will mess up the audio (crackling sounds, delay) on Ubuntu and Debian and other related distros. This PR adds a fix to this to make sure it works flawlessly on these specific distros.

[Encritary]

I got white screen when I installed OpenNBS for the first time through WINE. Installing dxvk through winetricks helped me. I'm using GTX 1050 Ti and official Nvidia drivers.

[Encritary]

It's better to create some sort of start.sh with all the env variables instead of aliasing wine for the whole user environment.

[ShinkoNet]

Yeah, I'd wait for a start.sh and adding mentions of dxvk before merging it to the readme.

Also, latest wine32on64 works with note block studio on the latest version of macOS, might add instructions on that too

[Bentroen]

Do these instructions still work?