`cargo component serve` does not show in `cargo component --help`

`cargo component serve` does not show in `cargo component --help` and this is because `serve` isn't a directly supported `cargo-component` command, like:

https://github.com/bytecodealliance/cargo-component/blob/50634428915707b34b49bebe85efb48ca82b27ca/src/bin/cargo-component.rs#L67-L76

And, instead, it is a `cargo` command (not really, but, as per the code's nomenclature, yes):

https://github.com/bytecodealliance/cargo-component/blob/50634428915707b34b49bebe85efb48ca82b27ca/src/lib.rs#L74-L83

I think it would be helpful to add `serve` as a proper `cargo-component` command for discoverability of the feature*.