Added NGEN Update.bat

Author: skycommand

README.md

@@ -42,6 +42,7 @@ A matter of licensing: I did not write this script. The user who posted it was c
 
 1. `Repair-AllVolumes.ps1`: Enumerates all fixed-disk volumes and sequentially runs `Repair-Volume` on them to scan them for errors.
 2. `Repair-Windows.ps1`: Repairs the online Windows instance by running DISM and SFC. Their logs are moved to the desktop.
+3. `NGEN Update.bat`: Runs NGEN inside Windows PowerShell. While PowerShell 6 and 7 run on .NET Core, Windows PowerShell and some Windows-exclusive PowerShell modules (which PowerShell 7 also loads) run on .NET Framework. Run this script with admin privileges whenever you update .NET Framework, or whenever you feel Windows PowerShell or PowerShell 7 for Windows are sluggish at launch time.
 
 ## Microsoft Antimalware