Document release process

## Why

We want to document the process to release a new official version of the DMQ node.

## What

Document the steps needed to create a pre-release and a release

## How

- [ ] Document the creation of a pre-release (with a new tag)
- [ ] Creation of a GitHub release with description and static binaries
- [ ] Creation of a Docker image
- [ ] Publication to CHaP
- [ ] Document the steps needed to qualify a pre-release
- [ ] Document the steps to officially promote a pre-release to a release
- [ ] Promotion of a GitHub release in pre-release
- [ ] Promotion of a Docker image
- [ ] Promotion of a CHaP package
- [ ] Document creation of a hotfix