feat: Automatically execute script after installation (#423)

assets/winvistax64.xml

@@ -259,6 +259,11 @@
           <CommandLine>reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /v "fAllowUnlistedRemotePrograms" /t REG_DWORD /d 1 /f</CommandLine>
           <Description>Enable RemoteAPP to launch unlisted programs</Description>
         </SynchronousCommand>
+        <SynchronousCommand wcm:action="add">
+          <Order>20</Order>
+          <CommandLine>cmd /C if exist "C:\OEM\install.bat" start "Install" "cmd /C C:\OEM\install.bat"</CommandLine>
+          <Description>Execute custom script from the OEM folder if exists</Description>
+        </SynchronousCommand>
       </FirstLogonCommands>
     </component>
   </settings>