Using pre-built releases with :ZkInstall

[mickael-menu]

:ZkInstall is currently building zk from scratch, which has a few advantages:

• Able to install the latest HEAD version
• Simpler to implement in zk.nvim
• It can build the right architecture needed by the user

But it also poses a few problems:

• The user must have the Go toolkit installed
• zk requires specific Go tags to build, which might change from one version to the other (see this PR for an example)
• The installed zk build will be "unversioned" and might not be 100% stable

An alternative could be to use the GitHub JSON API to fetch the latest pre-built releases from https://api.github.com/repos/mickael-menu/zk/releases/latest

This requires to know the architecture of the computer. If the architecture is not covered, we could always fall back on the go get solution.

[megalithic]

Great suggestion! Would offer more flexibility overall too.