Add comprehensive repository description with project details, tech stack, and model specification

[Copilot]

The repository lacked a clear description of its purpose, technology stack, and the LLM model deployed.

Changes

• Project overview: Added clear description as Terraform IaC for deploying a free-tier LLM server on OCI
• Technology stack: Listed Terraform, OCI (VM.Standard.A1.Flex), llama.cpp, and cloud-init
• Model specification: Documented TinyLlama-1.1B-Chat-v1.0 (GGUF Q4_K_M quantization)
• Structure: Organized readme into "What It Does", "Technologies Used", and "Quick Start" sections
• Details: Added VM specs (4 OCPUs, 24GB RAM), server port (8000), and relevant links

The README now serves as effective repository documentation instead of just setup commands.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.