feat: add function description support to FunctionEntry

[eddycharly]

Add function description support to FunctionEntry.

This will be useful for consumers of the lib to provide documentation around their custom functions.

cc @springcomp

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 88.85%. Comparing base (e430401) to head (7ab3366).
Report is 10 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #105      +/-   ##
==========================================
+ Coverage   88.51%   88.85%   +0.34%     
==========================================
  Files          15       15              
  Lines        2594     2621      +27     
==========================================
+ Hits         2296     2329      +33     
+ Misses        204      200       -4     
+ Partials       94       92       -2     

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

[eddycharly]

@springcomp are you ok with this change ?

[springcomp]

Great idea !