Query endpoint takes a query and returns an answer
on the basis of retrieved similar docs.
Thought about the name and realized that qna makes
much more sense than query, as it takes a query
and returns an answer
This commit enables anyone to create a app and add 3 types of data
sources:
* pdf file
* youtube video
* website
It exposes a function called query which first gets similar docs from
vector db and then passes it to LLM to get the final answer.
