[Task]: Document new push process for addons-server

[KevinMind]

Description

We now release addons-server via github releases and should update the push duty documentation to reflect this.
I will also take the opportunity to update any stale info and restructure the doc to better focus information based on topics.

Acceptance Criteria

Milestones/checkpoints

Beta Give feedback

1. Someone can release addons-server following the new docs
2. The docs are well organized
3. THere is no stale or outdated information in the docs

Checks

• If the issue is ready to work on, I have removed the "needs:info" label.
• If I have identified that the work is specific to a repository, I have removed "repository:addons-server" or "repository:addons-frontend"

┆Issue is synchronized with this Jira Task