Editorial: Add an example of using ordered map syntax for dictionaries. (#775)

Ref. #142.

Author: Ms2ger

index.bs

@@ -4767,6 +4767,20 @@ specific dictionary |D| if all of its [=map/entries=] correspond to [=dictionary
 correct order and with the correct types, and with appropriate [=map/entries=] for any required
 dictionary members.
 
+<div class="example">
+    <pre highlight="webidl">
+    dictionary Descriptor {
+      DOMString name;
+      sequence&lt;unsigned long> serviceIdentifiers;
+    };
+    </pre>
+
+    A <code>Descriptor</code> dictionary could be created as in the following steps:
+
+    1.  Let |identifiers| be « 1, 3, 7 ».
+    1.  Return «[ "name" → "test", "serviceIdentifiers" → |identifiers| ]».
+</div>
+
 <p class="advisement">
     As with [=optional argument/default value|operation argument default values=],
     it is strongly suggested not to use <emu-val>true</emu-val> as the