chore: Update rag_engine with package installations

fix: Use correct package name google-search-results instead of serpapi

fix: Add missing serpapi dependency

Update app and RAG engine

docs: Comprehensive README update with installation, usage, tech stack, and troubleshooting sections

Merge branch 'main' of https://github.com/artistica-004/multi-pdf-chatbot

Update: Add agent.py, modify app.py and rag_engine.py, remove deprecated streamlit_app.py

Update README.md

Add python-dotenv to requirements

Fix colorTo value

Add HuggingFace README config

Add README and fix conflicts

initial commit

Duplicate from streamlit/streamlit-template-space

Remove .env and add gitignore

Multi PDF Chatbot first commit