Add multiple docs format support

[NirantK]

Use: https://github.com/Unstructured-IO/unstructured

For reference, look at how SQLite Utils are organised. These are optional and someone not using them — never needs to care about them

Desired Workflow: Someone points to a pdf file → we read it → chunk it with context → convert to a JSON/Python object

Problem Motivation: Albus

Remember to mark this as an optional dependency in pyproject.toml