Update README.md for adding PowerShell cmdlet samples

[soroshsabz]

Brief description of your issue

ITNOA

Hi all,

Thanks to @denelon #1760 merged, I think it is good (and need) to update README.md for reference to PowerShell native cmdlet and add one PowerShell native sample (like first gif in above of README) to show power of native cmdlet

[soroshsabz]

• related to Add Native PowerShell Support #221
• related to When do we begin to see the PowerShell cmdlets? #674
• related to PowerShell CLI Friendly #1088

[soroshsabz]

I suggest add Microsoft.WinGet.Client into App installer by defaults