Add reverse image search docs

[Adityav369]

No description provided.

[jazzberry-ai]

Bug Report

Name	Severity	Example test case	Description
Missing error handling for reverse image search without use_colpali=True	Medium	Call retrieve_chunks or retrieve_chunks_grouped with query_image but without setting use_colpali=True. Observe that the code does not raise an error or warning.	The documentation states that use_colpali=True is required for reverse image search using query_image. However, the code snippets do not include error handling for the case where query_image is provided but use_colpali=True is not set. This can lead to confusing behavior for users.

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