docs: update install doc with Winget (#693)

README.md

@@ -29,9 +29,12 @@ To remedy this, **Topgrade** detects which tools you use and runs the appropriat
 - NixOS: [Nixpkgs](https://search.nixos.org/packages?show=topgrade)
 - Void Linux: [XBPS](https://voidlinux.org/packages/?arch=x86_64&q=topgrade)
 - macOS: [Homebrew](https://formulae.brew.sh/formula/topgrade) or [MacPorts](https://ports.macports.org/port/topgrade/)
-- Windows: [Scoop](https://github.com/ScoopInstaller/Main/blob/master/bucket/topgrade.json)
+- Windows: [Scoop][scoop] or [Winget][winget]
 - PyPi: [pip](https://pypi.org/project/topgrade/)
 
+[scoop]: https://scoop.sh/#/apps?q=topgrade
+[winget]: https://winstall.app/apps/topgrade-rs.topgrade
+
 Other systems users can either use `cargo install` or the compiled binaries from the release page.
 The compiled binaries contain a self-upgrading feature.