fix broken url link in docs

[drewverlee]

this page http://metosin.github.io/compojure-api/doc/compojure.api.middleware.html has a broken link https://github.com/metosin/muuntaja/wiki/Configuration.

as does this page https://github.com/metosin/compojure-api/blob/master/CHANGELOG.md with this broken link https://github.com/metosin/muuntaja/wiki/Configuration

It probably should be this https://github.com/metosin/muuntaja/blob/master/doc/Configuration.md