Add: demo for notes in namespace on classDialog

demos/classchart.html

@@ -183,6 +183,19 @@
     </pre>
     <hr />
 
+    <pre class="mermaid">
+      classDiagram
+        note "This is a outer note"
+        note for Class1 "This is a outer note for Class1"
+        namespace ns {
+          note "This is a inner note"
+          note for Class1 "This is a inner note for Class1"
+          class Class1
+          class Class2
+        }
+    </pre>
+    <hr />
+
     <script type="module">
       import mermaid from './mermaid.esm.mjs';
       mermaid.initialize({