Feature: implement a cargo component add command.

[peterhuene]

Now that cargo-add has been merged into cargo proper, we should definitely have an analogous command for cargo-component.

Something as simple as cargo component add --version 0.1.0 foo.wit editing Cargo.toml to include:

foo = { version = "0.1.0", path = "foo.wit" }

And cargo component add --version 0.1.0 --export foo.wit adds:

foo = { version = "0.1.0", path = "foo.wit", export = true }

[peterhuene]

I imagine in the future this command would be updated to add references to components from a registry:

cargo component add foo

[saulecabrera]

What do you think about modifying the command slightly to take a --path argument to signal that it should reference a local wit definition? Something like:

cargo component add --path /path/to/foo.wit --version 0.1.0 foo

Omitting the --path argument (or perhaps introducing a different argument) could signal referencing a component from a registry in the future.

The advantage that I see is that this approach is that it is standard with the definition of the component.dependencies entries in the Cargo.toml, in which the name of the wit files don't share a 1-1 relationship with the name of the component.

[peterhuene]

Indeed, I think what you propose makes the most sense and for now we can treat --path as required.

[peterhuene]

Implemented in #18.