Adding maintainer/releasing concepts to Governance

[roll]

What Data Package version are you using?

v2

Describe the Issue

I'm creating this issue based on the latest community call discussion.

We would like to add to the governance doc:

• a concept of maintainer of the standard itself (currently @roll and @peterdesmet)
• a releasing workflow (like this):
  • fixes need to be approved by one of maintainers (if a maintainer is a PR author - by the second one)
  • releases need to be approved by all the maintainers
  • Working Group doesn't need to vote on releases as they already voted for all the changes being subject of voting (just to save a little bit of their time)

Participation

• [ ] I am willing to submit a pull request for this issue.

[roll]

Hi @sapetti9, would you like to lead on this?