Support multiple architectures

[kjuulh]

Right now shuttle for example uses: amd64, even on m series macbooks. This means were loosing some performance as it has to run through rosetta 2. This is normally not a problem, but for binaries relying on a git native things such as go-git. It can severely hurt performance.

[kjuulh]

This could be done by templating the architecture variant within the string. Such as

shuttle-{{ .Architecture }}