Update winget install guide

Author: hustcer

README.md

@@ -49,7 +49,10 @@ $ nix profile install nixpkgs#nushell
 #### Windows:
 
 ```powershell
+# Install to user scope by default
 winget install nushell
+# Machine scope install(Run as admin or with sudo)
+winget install nushell --scope machine
 ```
 
 After installing, launch Nu by typing `nu`.

book/installation.md

@@ -3,6 +3,7 @@ next:
   text: Default Shell
   link: /book/default_shell.md
 ---
+
 # Installing Nu
 
 There are lots of ways to get Nu up and running. You can download pre-built binaries from our [release page](https://github.com/nushell/nushell/releases), [use your favourite package manager](https://repology.org/project/nushell/versions), or build from source.
@@ -27,7 +28,13 @@ For macOS and Linux, [Homebrew](https://brew.sh/) is a popular choice (`brew ins
 
 For Windows:
 
-- [Winget](https://docs.microsoft.com/en-us/windows/package-manager/winget/) (`winget install nushell`)
+- [Winget](https://docs.microsoft.com/en-us/windows/package-manager/winget/)
+
+  - Machine scope install: `winget install nushell --scope machine`
+  - Machine scope upgrade: `winget update nushell`
+  - User scope install: `winget install nushell` or `winget install nushell --scope user`
+  - User scope upgrade: Due to [winget-cli issue #3011](https://github.com/microsoft/winget-cli/issues/3011), `winget update nushell` will unexpectedly install the latest version to `C:\Program Files\nu`. The workaround is to run `winget install nushell` again to install the latest version for user scope.
+
 - [Chocolatey](https://chocolatey.org/) (`choco install nushell`)
 - [Scoop](https://scoop.sh/) (`scoop install nu`)