Deprecate the `cz_customize` convention and allow for overriding functionality

[Lee-W]

Description

Related: #1381 (comment)

Back when cz_customize was introduced, it was a brand-new convention that required users to design it from scratch without touching Python code. This might not be what the term "customize" indicates and has confused lots of our users.

Possible Solution

1. Rename cz_customize as cz_empty or something similar if we want to keep it
2. Allow existing conventions (e.g., cz_jira, cz_conventional_commit) to be overridden.

Additional context

No response

Additional context

No response

[AxTheB]

Hello. To start, I did a MR that adds customizing to conventional_commits. It can either be done to jira commitizen too, or moved to the base class, as you see fit.

[Lee-W]

I'm sorry for not getting back to you sooner. Crazy busy since July... (probably till mid Oct...) I have already assigned myself to take a look. Will try to do so when bandwidth allow. Thanks so much for helping out!

---

#1588 has more details on the user requirements. But let's keep the discussion here :)

[ryanrapini-bep]

+1 to this as i'm facing this now. For our purposes I want to run a much more cut-down version of cz that simply:

1. Only gives feat, fix, test, docs, chore, as my options as these are our general use cases
2. skips all other questions except "Write a summary of the code changes" and then "Is this breaking change y/n"

I started on customizing this and got this far:

[tool.commitizen]  # https://commitizen-tools.github.io/commitizen/config/
bump_message = "bump: v$current_version → v$new_version"
tag_format = "v$version"
update_changelog_on_bump = true
version_provider = "uv"
name = "cz_customize"

[[tool.commitizen.customize.questions]]
type = "list"
name = "change_type"
choices = [
  {value = "feat", name = "feat: A new feature. Correlates with MINOR in SemVer"}, 
  {value = "fix", name = "fix: A bug fix. Correlates with PATCH in SemVer"}, 
  {value = "test", name = "test: Test Additions."}, 
  {value = "docs", name = "docs: Documentation Additions."}, 
  {value = "chore", name = "chore: Maintenance/cleanup work"}
]
message = "Select the type of change you are committing"

[[tool.commitizen.customize.questions]]
type = "input"
name = "message"
message = "Write a short and imperative summary of the code changes"

but it's simply not worth the amount of time I've put into this as I was hoping for something drop-in with easy customization and I gave up trying to figure out how to re-implement the "Breaking change y/n" feature.

At the bare minimum it would be nice to have in the docs the current default workflow re-created in cz_customize in .toml format so that users could quickly grab that and tweak it. as it is now I feel as if I am trying to re-invent the whole library to get some minor tweaks for myself. happy to contribute