Scoop: Ability to install pre-release versions from GitHub

[notlmn]

For some apps downloaded from GitHub, scoop lets you install the latest version by using "github" field inside the "checkver" field of app manifest, but the release that scoop installs is the latest "Stable" release and not the "Pre-release" version.

There should be something like scoop install app --prerelease to get the latest pre-release version of the app from GitHub releases, maybe using the GitHub API.

[notlmn]

Some example GH apps using pre-releases:

• clink
• alacritty

[rasa]

We have a few “beta” releases in the versions bucket, like
https://github.com/scoopinstaller/versions/blob/master/bucket/7zip-beta.json

[notlmn]

We have a few “beta” releases in the versions bucket, like
scoopinstaller/versions:bucket/7zip-beta.json@master

That's kinda neat, but what I would like to propose is for scoop to use a field (like "channels") in the config file, to be able to scoop install 7-zip --channel beta (similar to Linux Snaps).

In case of GitHub hosted apps, this would be way easier, as you do not even have to configure it (--prerelease should do it, which would map to beta channel in config file if that field exists).