This is to be on par with the previous documentation.

As we are pretty much committed to github actions, we should
probably rely on it to push the images on tag.

This covers the missing bits.

	- update chart versions
	- update release documentation
	- Christian and David are the chart maintainers

	This is #152, #139, #127 in disguise.

	Maybe this time let it simmer a bit longer until the k8s
	release is there?

	Drop bit in the docs about updating image tag - not necessary
	if you use the instructions.

	This is a follow-up to #150, so we can get a 1.4.x release
	out that will be geared towards k8s 1.1[6-8].

	Update to latest 1.17 kubectl: 1.17.7.

	Tested on minikube with k8s 1.16.8, 1.17.4, 1.18.1

	Also point out how to create the dockerhub.yaml file,
	update other release related instructions.

	closes: #97