Add release process description to README.

[BigBlueHat]

Figured we should document this so others can follow it in future (and improve on it eventually).

[iherman]

Don't we need something about how to publish on cdn.jsdelivr.net?

[davidlehn]

The pattern presented here is problematic. It is storing large built files in git history forever. This will continue to grow bloat in the source repo that is otherwise small. I suggest using a npm process.
#4

I have access to publish packages now. Including build artifacts in the packages uploaded to npm and omitting them from source control is a common best practice. The only user difference will be a slightly different CDN URL. I think the only main issue here is it would be good to have a backup person or two with access to publish the package.

[iherman]

Just asked @deniak for an account, @davidlehn.

[BigBlueHat]

Merged this as (despite it's less than ideal nature) this is how we do it today...so it merits documentation. We can look to #4 or other for future improvement.