[Feature Request] Cookbooks for search types

## Problem Description
Create cookbooks to demonstrate use of different `search_type` for PgVector 

## Proposed Solution
In the `cookbook/agent_concepts/knowledge` directory create a new folder `search_type` and populate it with different `search_type` examples using PgVector

[Docs on how to get started
](https://docs.agno.com/vectordb/pgvector)