Handle pre-release channels

[taorepoara]

Is your feature request related to a problem? Please describe.
I can't properly create the beta versions of my project.

Describe the solution you'd like
Manage pre-release depending on the current branch and a list of the pre-release branches in a config file.

Describe alternatives you've considered
Instead of getting the pre-release channel (for example beta) with the config and the current branch, the user could give the channel in the version sub-command.

Additional context
Here is how semantic-release handle it: https://github.com/semantic-release/semantic-release/blob/cd6136d67ee83b262a34dd7a230e1e3ae4799ed0/docs/usage/workflow-configuration.md#pre-release-branches

The advantage of this tool over semantic-release (in my opinion) is that you just calculate the next version and change-log file when semantic-release goes to far.

[hdevalke]

so what you want is to enchance the .versionrc version file to include:

branches:
  - master
      name: beta
      prerelease: true
  - alpha-branch
      name: alpha
      prerelease: true

which then adds to the version 1.0.0-beta.1 or 1.0.0-beta.2 .. or 1.0.0-alpha.1 .. depending on the branch convco version is ran.

When the pre-release is set to false it would then ignore this and just set the version to 1.0.0?

Another option would just to add the property prerelease: <name> in the .versionrc file. As this could be changed easily in the branch. E.g. in master this could be prerelease: beta and in alpha-branch this could be pre-release: alpha.

or would it be better to provide convco version --prerelease beta which would imply convco version --bump --prerelease beta and let it up to the ci script/pipeline to set the right version e.g. based on a label of the pull request or in any other way?

What do you think is the most convenient way?

[taorepoara]

Both would be nice and do the job, but the most permissive (and maybe the simplest) would be to provide the prerelease param to the cli: convco version --prerelease beta to get the latest beta prerelease of the current branch and convco version --bump --prerelease beta to get the next beta prerelease.