Set ghc-8.6.3 as the recommended version
It seems to work well with current ecosystem and stackage has just introduced 8.6.3 as part of lts-13.1: https://www.stackage.org/lts-13.1
It seems to work well with current ecosystem and stackage has just introduced 8.6.3 as part of lts-13.1: https://www.stackage.org/lts-13.1