Fix up the sample wizards

They stopped working because the "Demos" tiddler went away

editions/tw5.com/tiddlers/samples/SampleWizard.tid

@@ -7,4 +7,4 @@ This is a modal wizard dialogue, stored in the tiddler SampleWizard.
 
 {{Motovun Jack.jpg}}
 
-You can <$button message="tw-modal" param="Demos" class="btn btn-inverse">nest wizards</$button>.
+You can <$button message="tw-modal" param="SampleWizard2" class="btn btn-inverse">nest wizards</$button>.

editions/tw5.com/tiddlers/samples/SampleWizard2.tid

@@ -0,0 +1,8 @@
+title: SampleWizard2
+tags: demo
+subtitle: I'm another modal wizard
+footer: <$button message="tw-close-tiddler" class="btn btn-primary">Close</$button>
+
+This is another modal wizard dialogue, stored in the tiddler SampleWizard2.
+
+You can <$button message="tw-modal" param="SampleWizard" class="btn btn-inverse">nest wizards</$button>.