Add changelog

[willhickey]

Problem

• Release notes are written from commit messages which are usually not written for end users.
• We don't track upgrade notes which causes confusion when config changes are required.

Summary of Changes

• Add a change log to facilitate writing and tracking release notes.

[willhickey]

The instructions in the change log seem complex but I believe they

1. are the minimum necessary protocol for tracking upgrade notes within our existing release process; and
2. will quickly become intuitive once we get used to them.

[stale[bot]]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[willhickey]

I've removed the branch tracking complexity that I had in earlier versions. I think we can manage that complexity using git diff. The new approach is simpler for authors and should be more powerful for consumers who can now diff between arbitrary versions.

[mvines]

I feel like we're all pretty close on this one, would it be more efficient to conclude the remaining discussion over a call?

[willhickey]

I setup a call for Monday (June 12). Ping me if you'd like to be added.

[willhickey]

@t-nelson Sorry I forgot to merge your suggestion. I think this is ready now

[willhickey]

ok let's try it. next step: herd the cats to get buy in to doing this. probably need a team-wide training session :)

I see we've got an all hands next week. If there's room in the agenda I'd be happy to do a bit about this. I'm thinking 3 minutes, with a focus on "why". I can follow that up with a separate call later in the week to answer any questions and talk through the "how" in more detail.