Finally releasing 4.0

This has been brewing in the dev branch for a while but we've now finally released 4.0 and we hope the transition will be relatively smooth 🤞

This is a larger release were we're restructuring a bit. We're pulling configs out of this repo as they constantly needs to be updated and it's very noisy to the main project development. We need to find better ways of collaborating on keeping them up to date in their new repo.
https://github.com/haugene/vpn-configs-contrib

We're also reverting back to using Ubuntu instead of alpine and we're changing the web proxy for those using that. Hopefully this will take us in a good direction with more stability and easier maintenance.

For any thoughts or questions, see the 4.0 discussion thread: #1936