Support for custom external registries

[ewgenius]

Hello!

I have a few components in mind that I would like to make installable through the shadcn-ui cli. However, I don't think it would be worth adding them to the repository.

It would be great if we could do something like this instead:

Let's assume that I have stored my components in my own repository and published them at https://ui.example.com, along with a shadcn-ui compatible registry index.
Then I install my custom components by using the optional parameter registry:

npx shadcn-ui@latest add my-custom-component --registry https://ui.example.com

Do you have anything like this in plans? I'd be happy to contribute if the proposal aligns with them.

Here is the small draft with basic changes needed to enable this #2409

[ewgenius]

Turned out I can do that just by COMPONENTS_REGISTRY_URL env variable. But it still would be nice to have official support for this.

[ewgenius]

closing this, new cli solves this

@shadcn awesome work, thank you!