Added reading list functionality

[WuYihong]

It is recommended to add a "reading list" feature similar to the Brave web browser. I don't use Pocket, and its need to log in makes me not want to use it. Particularly useful is the Brave Web browser's "reading list" feature, which marks what has been read as "read."

[siffemcon]

If you already haven't, you should also post that at https://connect.mozilla.org/t5/ideas/idb-p/ideas.