docs(upgrade): add missing word (#3125)

Author: svenheden

public/docs/ts/latest/guide/upgrade.jade

@@ -1436,7 +1436,7 @@ code-example(format="").
   #### Generate links for each phone
 
   We no longer have to hardcode the links to phone details in the phone list. 
-  We can generate them data binding each phone's `id` to the `routerLink` directive
+  We can generate them by data binding each phone's `id` to the `routerLink` directive
   and let that directive construct the appropriate URL to the `PhoneDetailComponent`:
 
 +makeExample('upgrade-phonecat-3-final/ts/app/phone-list/phone-list.template.html', 'list', 'app/phone-list/phone-list.template.html (list with links)')(format='.')