Update index.html

Co-authored-by: Jan-Ivar Bruaroey <jan-ivar@users.noreply.github.com>

index.html

@@ -872,7 +872,7 @@ <h2><dfn>CaptureController</dfn></h2>
                     <td><dfn>[[\IsBound]]</dfn></td>
                     <td><code>false</code></td>
                     <td>
-                      Tracks whether an application has attempted to associate [=this=]
+                      Whether an application has attempted to associate [=this=]
                       with a [=capture-session=], by providing it as a value to
                       {{CaptureController/setFocusBehavior()}}.
                     </td>