Add docs for the R2 Data Catalog

### Proposed changes

Proposed:
- https://developers.cloudflare.com/r2/iceberg-rest-catalog/

### Subject Matter

R2 Data Catalog 

### Content Location

This will be a new section with multiple documents providing information about the new product, R2 Data Catalog in addition to instructions on how to use it.

### Additional information

_No response_