Write a Solana program that generates wallet addresses on-chain and raw transactions.

We need a Solana Program with the following two features:

Feature A: Generate wallet addresses on-chain.
Feature B: Generate a raw transaction on-chain and sign it using a private key.

Deliverables:
- Solana Program wirtten in Rust.
- Deployed on Devnet
- A readme.md file that explains steps necessary for deploying on Solana Devnet