[DOCS] Documentation reorganization

[jaychia]

1. Groups all "learning materials" under Daft User Guide
2. Groups all other misc. materials under FAQ
3. Misc cleanups (broken links in API docs etc)

TODO:

1. Partitioning guide
2. Cheatsheet

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (b4f3ae1) 85.19% compared to head (5b75ff9) 84.76%.
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1762      +/-   ##
==========================================
- Coverage   85.19%   84.76%   -0.43%     
==========================================
  Files          55       55              
  Lines        5518     5554      +36     
==========================================
+ Hits         4701     4708       +7     
- Misses        817      846      +29     

Files	Coverage Δ
daft/context.py	72.04% <ø> (ø)

... and 5 files with indirect coverage changes