Documentation: Bundle

[YanisaHS]

Docs page: https://juju.is/docs/juju/bundle

Docs source: https://discourse.charmhub.io/t/bundle/1158

Issue: Just a suggestion, but I think overlay and regular should be switched around in the bulletpoints (or in the sentence before). Right now, it says there's two kinds "regular and overlay", but then it lists them in opposite order. It'd be clearer to have them in the same order as they were originally presented