Update installation in readme

Author: Kapil Borle

README.md

@@ -57,6 +57,12 @@ Installation
 Install-Module -Name PSScriptAnalyzer
 ```
 
+**Note** For PowerShell version `5.1.14393.206` or newer, before installing PSScriptAnayzer, please install the latest Nuget provider by running the following in an elevated PowerShell session.
+```powershell
+Install-PackageProvider Nuget –force –verbose
+Exit
+```
+
 #### Requirements
 
 ##### Windows