Define our system of releasing updates to wordpress-to-github

[chachasikes]

As we grow and add more publishing sites, we need to be able to slow down the update process and ship code that is vetted and notify teams when a change is being made.

We have a ticket already about starting to use tags.

This issue is about deciding on our process for notifying content teams, planning updates, and making sure that changes do not effect production sites.

We also need a mechanism to get feedback of any issues and for supporting.

Moving to versioned code will help subscribers to upgrade or rollback services in the event of an issue.