doc: update vyper.fun hyperlink

[charles-cooper]

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Cute Animal Picture

[codecov-commenter]

Codecov Report

Merging #2740 (98b1ab6) into master (2dc2478) will increase coverage by 0.04%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2740      +/-   ##
==========================================
+ Coverage   87.23%   87.28%   +0.04%     
==========================================
  Files          93       93              
  Lines        9893     9884       -9     
  Branches     2470     2467       -3     
==========================================
- Hits         8630     8627       -3     
+ Misses        781      778       -3     
+ Partials      482      479       -3     

Impacted Files	Coverage Δ
vyper/semantics/types/indexable/sequence.py	87.60% <0.00%> (-0.50%)	⬇️
vyper/codegen/expr.py	81.46% <0.00%> (+0.38%)	⬆️
vyper/ast/pre_parser.py	96.82% <0.00%> (+5.78%)	⬆️

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[charles-cooper]

superseded by #2815