Clarify widthSelectionMultiplier documentation

docs/graph.html

@@ -1239,7 +1239,7 @@ var options = {
     <td>widthSelectionMultiplier</td>
     <td>Number</td>
     <td>2</td>
-    <td>This determines the thickness scaling of an edge if it, or a node it is connected to, is selected.</td>
+    <td>Determines the thickness scaling of an selected edge. This is applied when an edge, or a node connected to it, is selected.</td>
   </tr>
 </table>