explain interactivity support

index.html

@@ -18,11 +18,14 @@
     <div id="content">
       <h1>&#9728;&#65039; Xet Storage Sunburst &#9728;&#65039;</h1>
       <p>
-        This sunburst diagram represents all public data stored using Xet. The
-        diagram presents this information hierarchically first by repo type
+        This sunburst diagram represents all public data stored using Xet. 
+			</p>
+			<p>
+				The diagram presents this information hierarchically first by repo type
         (model, dataset, or space) then owner (user or org), repo name, and
         finally individual files within the repo backed by Xet.
       </p>
+			<p>Click a node to zoom in, or the center to zoom out.</p>
       <svg id="sunburst"></svg>
     </div>
   </body>