feat: provide example for kubo RPC auth

[SgtPooki]

Kubo just merged RPC auth support: ipfs/kubo#10187 and we should make sure kubo-rpc-client has an example showing how users would talk to a Kubo that has enabled auth secret.

[lidel]

+1, we should have example in https://github.com/ipfs/js-kubo-rpc-client#example with basic:user:pass and bearer:token scenarios.

cc @hacdias mind testing and updating https://github.com/ipfs/js-kubo-rpc-client#example to include it? (and fix the library if we don't have ability to set up Authorization header yet)

[hacdias]

Well, we kinda have the example already: https://github.com/ipfs/js-kubo-rpc-client#custom-headers 😅 I will expand on them to include Basic Auth.