Prefer pwsh.exe over powershell.exe in documentation

[casey]

Fixes #2604.

@john-cd Since which version of windows is pwsh.exe installed on by default? I want to make sure it's widely available before changing the docs.

[john-cd]

Not the expert, but the transition from "Windows PowerShell" to cross-platform "PowerShell" started with PowerShell Core 6, GA on January 10, 2018. We are now at "Powershell 7.5": https://en.wikipedia.org/wiki/PowerShell

Now, MS designed old Windows PowerShell and new Powershell to run side-by-side.

"Windows PowerShell is the version of PowerShell that ships in Windows. This version of PowerShell uses the full .NET Framework, which only runs on Windows. The latest version is Windows PowerShell 5.1. Microsoft is no longer updating Windows PowerShell with new features." https://learn.microsoft.com/en-us/powershell/scripting/what-is-windows-powershell

So MS still ships Windows PowerShell, but for a couple of years there has been a nag message that prompts you to install cross-platform Powershell aka pwsh.exe.

So, developers could use both but most likely have upgraded to pwsh

[casey]

Hmm, interesting. @runeimp do you happen to know? I'd like to change all the docs to use pwsh.exe instead of powershell.exe, but want to make sure that pwsh.exe is available by default on enough recent versions of windows.