Add note in named graphs on the use of @included in preference to @graph for JSON-LD 1.1 usage.

Author: gkellogg

index.html

@@ -8996,6 +8996,10 @@ <h3>Using the Document Base for the Default Vocabulary</h3>
     <code>@graph</code> keyword collects such nodes in an <a>array</a>
     and allows the use of a shared context.</p>
 
+  <p class="note">More common usage in JSON-LD 1.1 would be to use the `@included` keyword
+    for such cases, and limit the use of `@graph` to describe <a>named graphs</a>.
+    See <a href="#included-nodes" class="sectionRef"></a>.</p>
+
   <aside class="example ds-selector-tabs changed"
          title="Using @graph to explicitly express the default graph">
     <div class="selectors">