Feature request: install a spoon from a git repository

[offbyone]

This is similar to #255, but it's not the same thing.

I'd love it if SpoonInstall supported unpackaged spoons in a git repository. Allow the addition of a git repo to the repos list like this:

spoon.SpoonInstall.repos.unpacked = {
  url = "https://github.com/offbyone/Spoons",
  layout = "git",
  desc = "My personal spoons",
  ref = "main",
}

The layout would be:

root/
  Spoons/
    MyNiftySpoon.spoon/
      init.lua
      README.md
    MyLessImpressiveButStillCoolSpoon.spoon/
      init.lua
  README.md

This would open up the ability to host spoons in a much less painful way -- I know, because I have a relatively complex GitHub Actions setup to build the spoon zip for my own spoons repository too! -- by simply having a git repository at the URL that contains the spoon code, and instead of having to have Spoons/*.spoon.zip in the repository, the developer could have the uncompressed Spoon content.

I'd propose a couple of options out of the gate for flexibility:

• ref should support tags, branches, and pinned refs
• relative_path should default to Spoons/ but could be configured

spoon.SpoonInstall's installation commands would act by cloning the repository, checking it out to the specified ref, and copying the spoon into the correct place.

[offbyone]

I should note, I'm willing to have a look at the SpoonInstall code myself and take a stab at implementing this, if this is a feature you'd be interested in.

[cmsj]

@offbyone that sounds like a good feature, feel free to have a look at it!