Add documentation about release process

[SaschaSchwarze0]

We should document the order of what all needs to be done in which project to rollout a release, build, cli, operator, website.

[SaschaSchwarze0]

Will put something in hackmd so that we can easily extend during this week.

[SaschaSchwarze0]

Here it is: https://hackmd.io/OMxlKFgaSsGEsO5TaQgieg