extend: append to prefixUrl

[mfulton26]

I'd like a way to use extend() and append to the existing prefixUrl:

const api = ky.create({ prefixUrl: "https://www.example.com/api" });
const sales = api.extend({ path: "sales/v1" });
await sales.post("offers", { json: {} }); // POSTs to https://www.example.com/api/sales/v1/offers

Today if I use prefixUrl in an extend() call then it overwrites the "base" prefixUrl and I don't see any way to access the configured prefixUrl from the "base" KyInstance. Is this already possible and I've overlooked it?

[sindresorhus]

I think something like this would be useful. It should probably be called appendPath to make it clear what it does. I would like to see feedback more people first though.

[DCKT]

+1 ! This functionality can be useful when an API has multiples levels.
I also think this should be under a new function to avoid breaking change and explicit behavior.

[mfulton26]

kyInstance.appendPath() could be nice (explicit, simple, no changes to extend())