docs: improve drag & drop demo details

src/app/examples/grid-drag-recycle.component.html

@@ -13,8 +13,8 @@ <h2>
   <h6 class="subtitle italic">
     <ul>
       <li>Click to select, Ctrl-click to toggle selection(s).</li>
-      <li>Drag one or more rows by the handle icon to reorder.</li>
-      <li>Drag one or more rows by selection and drag to the recycle bin to delete.</li>
+      <li>Drag one or more rows by the handle icon (1st column) to reorder.</li>
+      <li>Drag one or more rows by selection (2nd or 3rd column) and drag to the recycle bin to delete.</li>
     </ul>
   </h6>
 
@@ -46,4 +46,4 @@ <h6 class="subtitle italic">
       </div>
     </div>
   </div>
-</div>
+</div>