docs: add cybersiddhu as a contributor

[allcontributors]

Adds @cybersiddhu as a contributor for code, maintenance.

This was requested by wildlifehexagon in this comment

[codecov]

Codecov Report

Merging #558 (ac4e14e) into develop (2051098) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #558   +/-   ##
========================================
  Coverage    49.27%   49.27%           
========================================
  Files           63       63           
  Lines          552      552           
  Branches        84       84           
========================================
  Hits           272      272           
  Misses         280      280           

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