title: Add key to NSDictionary (iPhone SDK)
body: <p>A really quickly trying to add a key to a .plist. I almost have it, what is the correct version of the fourth line?</p>
  <pre><code>    NSString *path = [[NSBundle mainBundle] pathForResource:@&quot;Favourites&quot; ofType:@&quot;plist&quot;];
      NSDictionary *rootDict = [[NSDictionary alloc] initWithContentsOfFile:path];
      [rootDict addKey:@&quot;Test&quot;]; //guessed code
      [rootDict writeToFile:path atomically: YES];
  </code></pre>