Add public qualifier in rule maker template string

Author: Kapil Borle

Utils/RuleMaker.psm1

@@ -87,7 +87,7 @@ namespace Microsoft.Windows.PowerShell.ScriptAnalyzer.BuiltinRules
     #if !CORECLR
     [Export(typeof(IScriptRule))]
 #endif
-    class {0} : IScriptRule
+    public class {0} : IScriptRule
     {{
         /// <summary>
         /// Analyzes the given ast to find the [violation]
@@ -483,4 +483,4 @@ Function Remove-Rule
 }
 
 Export-ModuleMember -Function Add-Rule
-Export-ModuleMember -Function Remove-Rule
+Export-ModuleMember -Function Remove-Rule