Description

To make commitizen integrate even better, new configuration keys hooks_pre_bump and hooks_post_bump were added to allow to run arbitrary commands prior to and right after running bump.

I've backported the work done by @janw and slightly adjusted it:

• updated the patch to apply against the latest version of commitizen
• run hooks_pre_bump hooks after the versions have been updated but before they are committed and tagged, so additional documentation can be generated with the new version or other generators can be run and staged.
• I couldn't think of a usecase why you would want to hook into the process of generating the changelog so I completely removed this part.

Checklist

• Add test cases to all the changes you introduce
• Run ./scripts/format and ./scripts/test locally to ensure this change passes linter check and test
• Test the changes on the local machine manually
• Update the documentation for the changes

Steps to Test This Pull Request

1. Add something like this in your commitizen config file:

[tool.commitizen]
hooks_pre_bump = [
  "touch foo.bar",
  "git add foo.bar"
]

2. Run cz bump and notice the Running hook output
3. Run git show HEAD to see foo.bar is part of the latest release

Additional context

Closes: #292
Thanks to @janw to do the heavy lifting here.