fix: Document the fact that rot90 is counterclockwise

[samestep]

Description

Previously the documentation for rot90 said that it rotates a point/vector clockwise. As far as I can tell, this is incorrect, so this PR modifies the documentation to say that it rotates counterclockwise.

Checklist

• I have commented my code, particularly in hard-to-understand areas
• My changes generate no new warnings
• New and existing tests pass locally using yarn test
• I ran yarn docs and there were no errors when generating the HTML site
• My code follows the style guidelines of this project (e.g.: no ESLint warnings)

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Latest commit:	0567cc9
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[codecov]

Codecov Report

Merging #711 (0567cc9) into main (3a0d6ac) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #711   +/-   ##
=======================================
  Coverage   66.89%   66.89%           
=======================================
  Files          44       44           
  Lines        7144     7144           
  Branches     1343     1343           
=======================================
  Hits         4779     4779           
  Misses       2356     2356           
  Partials        9        9           

Impacted Files	Coverage Δ
packages/core/src/contrib/Functions.ts	39.56% <ø> (ø)
packages/core/src/engine/Autodiff.ts	73.88% <ø> (ø)
packages/core/src/utils/Util.ts	24.70% <ø> (ø)

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