Update README with PowerShell module installation

Added installation instructions for AsBuiltReport.Core module.

Author: rebelinux

README.md

@@ -106,6 +106,9 @@ Local user privileges are required to run this report.
 ### PowerShell
 <!-- ********** Add installation for any additional PowerShell module(s) ********** -->
 ```powershell
+# Install AsBuiltReport.Core 1.5.0-RC1
+Install-Module AsBuiltReport.Core -Repository PSGallery -AllowPrerelease
+
 # Install
 install-module AsBuiltReport.System.Resources -Force
 
@@ -212,4 +215,4 @@ PS C:\> New-AsBuiltReport -Report System.Resources -Target localhost -Username '
 
 # Generate a System Resources As Built Report for 'localhost'. Export report to HTML & DOCX formats. Use default report style. Save reports to 'C:\Users\Jon\Documents' and set the report language to Spanish.
 PS C:\> New-AsBuiltReport -Report System.Resources -Target localhost -Username 'User' -Password 'P@ssw0rd' -Format Html,Word -OutputFolderPath 'C:\Users\Jon\Documents' -ReportLanguage es-ES
-```
+```