Documentation revamp

[BatyLeo]

• Use DocStringExtensions.jl
• Separate API between specific problems, losses, optim layers and internals
• Background page for math (optim + ML), focus on discrete functions rather than linear programs
  • explain chain rules
  • add math details on each feature
• Guide for choosing the right tool (as in https://scikit-learn.org/stable/tutorial/machine_learning_map/index.html)
• Lots of tutorials (remove GridGraphs from the graph tuto)
  • remove grid graphs from the graphs tutorial
  • add a tutorial with JuMP
  • showcase all features in the tutorial
  • demonstrate use of kwargs

[codecov-commenter]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (5584bbe) 89.78% compared to head (20ff86e) 89.76%.
Report is 3 commits behind head on main.

Files	Patch %	Lines
src/perturbed/additive.jl	0.00%	2 Missing ⚠️

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #102      +/-   ##
==========================================
- Coverage   89.78%   89.76%   -0.02%     
==========================================
  Files          24       24              
  Lines         695      694       -1     
==========================================
- Hits          624      623       -1     
  Misses         71       71              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.