docs: fix broken docs links to source

[wesbos]

A few of the docs links point to a /@shikijs/ folder that isn't needed any longer

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8984095) 96.29% compared to head (aa71d1a) 96.29%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #582   +/-   ##
=======================================
  Coverage   96.29%   96.29%           
=======================================
  Files          70       70           
  Lines        5617     5617           
  Branches      745      745           
=======================================
  Hits         5409     5409           
  Misses        204      204           
  Partials        4        4           

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