Fix install instructions to work on arm

[t3dium]

The install instructions currently assume the user is using x64, leading to it failing to fetch the correct binary on an arm architecture such as on raspberry pi's.

It'll now detect which arch is being used, and will use the appropriate package.

[t3dium]

Second commit adds arm32 which does make the command a bit too long, could leave it out given that most people will be using 64 bit.