Fix a typo in example (#7423)

fix a typo in example

editions/tw5.com/tiddlers/widgets/ParametersWidget.tid

@@ -52,7 +52,7 @@ These attributes provide low level access to the contents of the transcluding wi
 Here the <<.wlink ParametersWidget>> widget is used to declare a parameter whose default value is transcluded from another tiddler.
 
 <$macrocall $name='wikitext-example-without-html' 
-src="""\procedure mymacro
+src="""\procedure mymacro()
 <$parameters name={{$:/SiteTitle}} age="21">
 My name is <<name>> and my age is <<age>>.
 </$parameters>