Include a markdown CHANGELOG.md in the repo

[JustinBeckwith]

Today we have a CHANGES.md, but it looks like that isn't being kept up to date. The changes recorded in /releases look great - it would be nice to have these in CHANGLOG.md like the other languages as well though.

[grant]

I think this should be removed as this file is outdated. We can re-add the file when it is ready.

If we can close this with the above PR, can you please assign me to the issue?

[chingor13]

The split repos have this with our newest release tooling