Support install from scoop on Windows

[shpodg]

https://scoop.sh/

[yschimke]

https://github.com/lukesampson/scoop/wiki/Creating-an-app-manifest

[yschimke]

Testing https://gist.github.com/yschimke/3ae32fa5c7f324df5616e0bd433c36b9

[yschimke]

Working

[yschimke]

[yschimke]

Windows

gh is available via scoop, Chocolatey, and as downloadable MSI.
scoop

Install:

scoop bucket add github-gh https://github.com/cli/scoop-gh.git
scoop install gh

Upgrade:

scoop update gh

Chocolatey

Install:	Upgrade:
choco install gh	choco upgrade gh