Add module mapper book example

[laggui]

Checklist

• Made sure the book is up to date with changes in this PR.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.06%. Comparing base (53bc165) to head (117c6eb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2621   +/-   ##
=======================================
  Coverage   82.06%   82.06%           
=======================================
  Files         831      831           
  Lines      106003   106003           
=======================================
  Hits        86990    86990           
  Misses      19013    19013           

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