docs: add yeppin as a contributor for code

[allcontributors]

Add @yeppin as a contributor for code.

This was requested by yeppin in this comment

[codecov-commenter]

Codecov Report

Merging #235 (095f3c5) into main (4df75af) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #235   +/-   ##
=======================================
  Coverage   89.55%   89.55%           
=======================================
  Files          20       20           
  Lines         134      134           
  Branches       12       12           
=======================================
  Hits          120      120           
  Misses         14       14           

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