[DataCatalog2.0]: Add docs and docstrings for KedroDataCatalog

[ElenaKhaustova]

Description

Following the further plan for KedroDataCatalog — https://github.com/kedro-org/kedro/issues/3995#issuecomment-2419884227— we want to add docs explaining how to use it and docstrings so users can start testing it.

First we need to merge dict-like interface PR: #4218

Context

#4218 (review)

Possible Implementation

• Create a dedicated section in the docs and add API description with usage examples
• Revise docstrings and add missing