Add command to upsert data to Pinecone index

[Ashesh3]

Resolves #7
This PR adds a new command to upsert data to a Pinecone index. The command processes text documents in batches and creates embeddings for each batch using the OpenAI text-embedding-ada-002 engine. The embeddings are then upserted to a Pinecone index along with metadata. The command is able to handle txt, md, and pdf files. The code has been tested and is ready for review.

Steps

1. Place text or pdf files in upsert folder
2. Setup API keys in the env
3. Run python manage.py upsert

[skks1212]

LGTM