Support additional parameter names (single-dash, etc) about clidantic

[edornd]

Hey @gusutabopb, thank you for the good suggestion, in fact this was one of the major missing features.
Your proposal is quite neat, the only issue I have with it is that the existence of a cli kwarg is of course not explicitly stated since it's not native to pydantic, as well as the use of a dictionary it' not very "declarative", meaning that it's hard to know what to provide as input (thinking about IDE suggestions like IntelliSense).
At the same time this modification has a very low impact, which is nice.

A solution I was instead considering consisted in creating a custom CLIField inheriting Field, to provide this functionality this way (which requires a bit more work than yours, but probably not that much):

class Config(BaseModel):
    name: str = CLIField("-n", "--old-name", default="Mark", description="Your name", other_custom_cli_stuff="value")
    count: int = CLIField("-c")

Basically it would prioritize the functionality the CLI needs without interfering with pydantic. The main logic of CLIField would remain in the init, handling its custom fields and forwarding to super for the rest, in the right order.
Let me know what you think about this.

And thanks to you for giving this thing a try!