iOS: support sharing links in built-in story reader

Hi! I think it’d be a nice feature, if long click on a link in a built-in reader invoke a share menu.
Especially, option to add a link to a reading list would be nice. Currently the only reasonable workaround is to open the story in a real browser.
However, I’m not sure if it’s possible :slight_smile: If it’s not possible, I think the option to always open the story in a browser would be nice.