Mark post as read when scrolled past

[humanplayer2]

• [y] Did you check to see if this issue already exists?
• [ y] Is this only a single feature request? Do not put multiple feature requests in one issue.
• [n] Is this a question or discussion? Don't use this, use https://lemmy.ml/c/jerboa

** Describe the feature request below **

The Hide read posts option is great. I still see many of the same posts, because I don't open most posts. They are therefore not marked as read.

Having the option to mark posts as read when scrolled past would be nice.