[Feature Request] Provide a way to use pyproject.toml config together with additional CLI arguments

Request

Please provide a -c and --config argument in the CLI which can be pointed to a TOML configuration file such as pyproject.toml. This configuration would be used in combination with other CLI arguments. In the case of conflicts, an error should be raised.

Rationale

Thanks for creating this great tool!

I would like to be able to use this sort of configuration both with and without --dryrun (for local and CI respectively).

[tool.pre-commit-update]
all_versions = false
verbose = true
exclude = [
    "isort",
    # many other packages
]

My exclude list is quite long so at the moment I'm having to duplicate this configuration in two places, once in pyproject.toml and another time in the dryrun command. I'd prefer to be able to point to the pyproject.toml file but also add the --dryrun flag. So I could go

pre-commit-update --config pyproject.toml --dryrun