Fix links in docs

[andrzejressel]

closes #798

[codecov]

Codecov Report

Merging #800 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #800      +/-   ##
============================================
+ Coverage     41.01%   41.02%   +0.01%     
  Complexity      510      510              
============================================
  Files           277      277              
  Lines          7156     7156              
  Branches        815      815              
============================================
+ Hits           2935     2936       +1     
  Misses         3961     3961              
+ Partials        260      259       -1

Impacted Files	Coverage Δ	Complexity Δ
...src/main/kotlin/arrow/optics/instances/map_java.kt	94.28% <0%> (+2.85%)	0% <0%> (ø)	⬇️

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[raulraja]

Much needed 👏 👏

[pakoito]

Awesome work, love the new tool too! Thank you :D