Beachball canary isn't documented and doesn't work as would be expected

This is going to be a relatively wide ranging issue on the topic of the canary command.

1. There isn't any documentation on the Canary command. I had to figure it out for myself after noticing it mentioned once in the docs.
2. The bump algorithm on canary works a bit weirdly? My packages were on version 0.1.5 and I created a minor change. Running bump locally increased the version to 0.2.0 as expected. However, if I undo those changes and instead run canary I get 0.2.1-pr30.0 (where I'm using the PR number from bitbucket). This doesn't seem right, why am I bumping an extra patch version above where I should be?
3. It might be slightly related to the undocumented nature of the command, but as the bump is not committed back to git, how does canary know to go from .0 to .1 the next time a version is pushed?

I'm might be willing to look into this and submit a PR, but before I do I'd like my assumptions cleared up, just in case I'm barking up the wrong tree.

Start with the CLI documentation at the linked Bumping and Publishing Options page, then inspect the canary and bump command entry points and reproduce the 0.1.5 to 0.2.1-pr30.0 behavior. Done means the canary versioning behavior is resolved or explained, successive canary increments are understood, and the command is documented.