lib: better log message when ps fails

PR-URL: #2229
Reviewed-By: Bartosz Sosnowski <bartosz@janeasystems.com>
Reviewed-By: Rod Vagg <rod@vagg.org>

lib/find-visualstudio.js

@@ -151,7 +151,7 @@ VisualStudioFinder.prototype = {
 
     const failPowershell = () => {
       this.addLog(
-        'could not use PowerShell to find Visual Studio 2017 or newer')
+        'could not use PowerShell to find Visual Studio 2017 or newer, try re-running with \'--loglevel silly\' for more details')
       cb(null)
     }