Confusion between ODS and EDS when proving a share range

[rach-id]

Currently, we provide the API to prove a share range:

https://github.com/celestiaorg/celestia-app/blob/4f4d0f7ff1a43b62b232726e52d1793616423df7/pkg/proof/proof.go#L59-L73

The problem with this implementation is that it doesn't make the distinction between the ODS and the EDS. This creates the following confusion.

Given the following square:

• If we assume the API only prove ODS shares, then we're not providing a full API for Blobstream rollups. Since the sequence of spans can be any place in the square.
• If we assume the API provides EDS shares, then there is no way to reference share ranges that span across multiple rows. For example, share range: [10, 25] will contain the EDS shares + ODS shares, which is not the exact requested proof. Also, the share range will not have the same namespace and the API will return an error.

Moreover, while discussing the proofs, it will be good to extend the functionality of proof generation to support multiple namespaces per proof. But this can be left for a subsequent discussion.

Update: the API proves the ODS shares, which means that we're not providing the full API for Blobstream.

[rach-id]

Sync decision: instead of making code changes, we can just update the documentation everywhere to match the current API. And if there is demand for the improvements, we can discuss them then.