Document why `PackageVersion` is used in `PowerShell.Common.props` (#12523)
Document why `PackageVersion` is used in `PowerShell.Common.props` (#12523)

Co-Authored-By: Nick Guerrera <4bbe6463cdfbba0969975546ad242213ee3c349c@microsoft.com>
PaulHigin/PowerShell,TravisEz13/PowerShell,TravisEz13/PowerShell,daxian-dbw/PowerShell,JamesWTruher/PowerShell-1,PaulHigin/PowerShell,PaulHigin/PowerShell,daxian-dbw/PowerShell,JamesWTruher/PowerShell-1,TravisEz13/PowerShell,PaulHigin/PowerShell,JamesWTruher/PowerShell-1,TravisEz13/PowerShell,JamesWTruher/PowerShell-1,daxian-dbw/PowerShell,daxian-dbw/PowerShell