Sequence Navigation Buttons

[vaniver]

LW has some navigation abilities, but they're opaque and require many clicks.

At the end of each post in the Sequences, there should be a big green double left arrow button that leads to the start of the sequences, a left arrow button that leads to the previous post, a right arrow button that leads to the next post in the sequences, and a double right arrow button that leads to the least recent unread post in the sequences. (Maybe they shouldn't be arrows, and should be names instead?)

It seems like this is the sort of thing that should be done with the UI rather than editing all of the posts, especially since the least recent unread post should use some sort of cookie-based mechanism to determine which post to go to.

---

Minimum viable change: green button to point to next post in the sequences at the end of Eliezer's sequence posts.