consider making task_types input optional with a default

[dtanner]

Conventional commits have a well-established set of task types, and it would save a lot of configuration duplication if the action allowed a default value for the task_types input. e.g. ["feat","fix","docs","test","ci","refactor","perf","chore","revert"] like the docs example.

This would be a non-breaking change too. Thoughts?

[paduszyk]

I would even go with conventional-config used by commitlint: https://commitlint.js.org/reference/rules.html#type-enum.