The setup script is different for PowerShell7

[kuguma]

Suggest corrections to the documentation.

https://github.com/Schniz/fnm?tab=readme-ov-file#powershell

For PowerShell7, we need to specify power-shell (not powershell) with --shell. 😫😫😫

[ravindUwU]

I think power-shell is an alias for powershell, they both work for PowerShell 7, and the docs are correct? 🤔

fnm/src/shell/shell.rs

Lines 21 to 22 in ceee448

	#[clap(name = "powershell", alias = "power-shell")]
	PowerShell,

PS ~> fnm env --shell uwu
error: invalid value 'uwu' for '--shell <SHELL>'
  [possible values: bash, zsh, fish, powershell, cmd]