docs: add amayvs as a contributor for code

[allcontributors]

Add @amayvs as a contributor for code.

This was requested by markphelps in this comment

[codecov-commenter]

Codecov Report

Merging #668 (0108cb4) into master (f85f49c) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #668   +/-   ##
=======================================
  Coverage   83.43%   83.43%           
=======================================
  Files          16       16           
  Lines        1443     1443           
=======================================
  Hits         1204     1204           
  Misses        207      207           
  Partials       32       32           

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