Add registry entry with guid of the installed engine build and its path

Register-UnrealEngine.ps1

function Register-UnrealEngine 
{
    Get-Content ./Engine/Binaries/Win64/UE4Editor.version | %{$_ -imatch '"BuildId"[\s]*?:[\s]*?"(.*?)"'} | out-null

    if (!$? -and !(Test-Path Engine) ) { Write-Error "Engine directory not found" ; return }

    $Guid = "{$($Matches[1].ToString().ToUpper())}"
    $EnginePath = Resolve-Path . | %{ $_ -replace '\\','/' }

    New-ItemProperty -Path "HKCU:\Software\Epic Games\Unreal Engine\Builds" -Name $Guid -PropertyType String -Value "$EnginePath" -Force | out-null
    
    if (!$?) { Write-Error "Error occured while adding registry item." ; return }
    
    echo "`n`tUE4 build successfully registered. `n`n`t`tGuid:`t$Guid`n`t`t`Path:`t$EnginePath`n"
}