Fix some minor issues before 0.3.5

[johnynek]

I realized we used line instead of row in the LocationMap and we had a doc error that caused v0.3.5 publish to fail, so I figured I could fix that.

[codecov-commenter]

Codecov Report

Merging #305 (a6c7f5f) into main (af1bc74) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #305   +/-   ##
=======================================
  Coverage   96.75%   96.75%           
=======================================
  Files           9        9           
  Lines        1048     1048           
  Branches      101      101           
=======================================
  Hits         1014     1014           
  Misses         34       34           

Impacted Files	Coverage Δ
core/shared/src/main/scala/cats/parse/Caret.scala	100.00% <100.00%> (ø)
...shared/src/main/scala/cats/parse/LocationMap.scala	100.00% <100.00%> (ø)

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[johnynek]

I am going to exercise a rare self merge so we can get this published today.

I think consistency with LocationMap.toLineCol means we should use line in Caret.