Create versioning and release process announcement

[fpliger]

Checklist

• I added a descriptive title
• I searched for other issues and couldn't find a duplication
• I already searched in Google and didn't find any good information or help

What is the issue/comment/problem?

We now have chosen/implemented a versioning and release process. We need to document it and announce it. This issue is to capture that task.

Acceptance criteria:

• This information is added to the docs
• We have post announcing the changes
• Both above have clear instructions to users on how the process work and how users should upgrade/pin versions

[marimeireles]

This is done! :)