Fix gsl linking error on CF build for arm Mac

[Tieqiong]

@sbillinge please check, thanks

Remove mac static GSL linking logic, use shared.
Add gsl to conda requirements.
Change doc to docs for skpkg standard.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.97%. Comparing base (cd6d363) to head (adc03f4).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #144   +/-   ##
=======================================
  Coverage   98.97%   98.97%           
=======================================
  Files           6        6           
  Lines        1267     1267           
=======================================
  Hits         1254     1254           
  Misses         13       13           

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