Update MathJax URL
Update MathJax URL

MathJax is shutting down their CDN:
https://www.mathjax.org/cdn-shutting-down/

They recommend migrating to cdnjs.

haskell/haddock,Fuuzetsu/haddock,haskell/haddock,haskell/haddock,haskell/haddock,Fuuzetsu/haddock,Fuuzetsu/haddock,haskell/haddock,Fuuzetsu/haddock