upgrade-4-to-5.md

Upgrading from 4 to 5

Version 5 works with Navigation and Elm 0.17

Matchers

All matchers stay the same as in version 4.

Navigation

Navigation is now handled by the Navigation module. See example app at examples/basic/Main.elm. Hop doesn't return effects / commands anymore, this should be done by passing a path to Navigation.modifyUrl.