Create FAQ & Update Docs

[mrariden]

The following questions/issues are addressed in this PR:

FAQ section

• Transition from training to application in research #690 Model training tips: what accuracy is good enough
• nuclei Model #691 Downloading models for austere computing environments
• How does diameter affect the running results of cellpose? #686 What does diameter do?
• Multiclass segmentation support?
• Cellpose masks saving with darker at the top. #710 Why do mask files look like they do?
• Cellpose is frozen/broken

Documentation

• [BUG] Missing one argument in .npy file #659 Update flow colors
• Make sure no docs were lost in the auto CLI refactor
• Added Install Instructions for AMD GPUs #440 ROCm install info

[codecov]

Codecov Report

Merging #714 (0c0d00a) into main (ca88d6a) will increase coverage by 24.31%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             main     #714       +/-   ##
===========================================
+ Coverage   37.40%   61.71%   +24.31%     
===========================================
  Files          20       14        -6     
  Lines        5355     2936     -2419     
===========================================
- Hits         2003     1812      -191     
+ Misses       3352     1124     -2228     

see 9 files with indirect coverage changes

[carsen-stringer]

this looks great thanks!