Feature: Newly revamped vault page
Each section of the vault page is now broken into sub-sections.
The first section, "in progress", shows exercises you're currently working on. The next section, "recommended", shows the next exercises we recommend solving. After that is "coming up", which are the rest of the unsolved exercises in that section.
There's also "done" for exercises you've solved and "skipped" for exercises you've skipped.
We hope this new layout is more helpful than the giant list of exercises that showed up previously.
