Better changelog management

[snewcomer]

learna spits out versions that are hard to grok. Ideally, we could put in only non alpha/beta entries into our changelog, with the current beta/canary release at the top. Same goes for our release branch - we would only want the patch, minor and major releases and not all the beta/alpha's to show up.

[runspired]

yeah :/

I used to do that by hand. Would be nice to "collapse" the changelog.

[runspired]

I think we want to set the --from and --to properties when generating a new minor/major. For betas/alphas its fine to do "since the last alpha/beta".

This means that when generating a new minor/major/beta you have to delete all of the alpha changelog cruft when doing so.

[runspired]

closing in favor of tracking in #6103