Kirby 5 support

[maxhoffmann]

Are you planning to update this plugin to work with Kirby 5? Unfortunately the plugin API seems to have changed.

[dewey]

Yes! Still have to update my personal blog too, should be in the next 2 weeks.

[dewey]

@maxhoffmann I've just tested this with my Kirby 5 installation and it all seems good. There's a branch with the latest changes so in case you want to give it a go feel free to do so :)

#11