Update Nonlinear CCD Docs

[zfergus]

Description

Update Nonlinear CCD documentation.

Type of change

• Enhancement (non-breaking change which improves existing functionality)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 96.70%. Comparing base (b28b3c0) to head (6cf05c9).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #146      +/-   ##
==========================================
+ Coverage   96.69%   96.70%   +0.01%     
==========================================
  Files         109      109              
  Lines        7742     7742              
==========================================
+ Hits         7486     7487       +1     
+ Misses        256      255       -1     

Flag	Coverage Δ
unittests	96.70% <100.00%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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