Update README with project documentation

README.md

@@ -1,3 +1,79 @@
+# Static Exchange
 
-env file
-https://www.notion.so/Static-frontend-env-9e7224d8da0d4979857e04b8bf7f1f31?pvs=4
+Lightning-fast cross-chain cryptocurrency swaps between stablecoins and Bitcoin via the Lightning Network.
+
+## Overview
+
+Static Exchange is a web application that enables users to swap tokens across Polygon, Solana, and Tron networks using Lightning Network-secured escrow (HTLC) contracts. It supports XSGD on Polygon, USDC on Solana, and USDT on Tron.
+
+## Features
+
+- **Cross-chain swaps** between Polygon, Solana, and Tron via Lightning Network
+- **Multi-wallet support** including Web3Modal (Polygon), Backpack, Coinbase, Ledger, and Solflare (Solana)
+- **QR code generation** for Lightning invoices
+- **Real-time order tracking** with live status updates
+- **HTLC escrow** using SHA256 preimage-based atomic swaps
+
+## Tech Stack
+
+- React 18 with TypeScript
+- Tailwind CSS
+- Apollo Client (GraphQL)
+- Ethers.js / Solana Wallet Adapter
+- WebLN
+
+## Getting Started
+
+### Prerequisites
+
+- Node.js (v16 or later)
+
+### Environment Variables
+
+Create a `.env` file in the project root:
+
+```
+REACT_APP_WALLET_CONNECT_PROJECT_ID=<your-walletconnect-project-id>
+```
+
+See the [environment setup guide](https://www.notion.so/Static-frontend-env-9e7224d8da0d4979857e04b8bf7f1f31?pvs=4) for details.
+
+### Installation
+
+```bash
+npm install
+```
+
+### Development
+
+```bash
+npm start
+```
+
+Runs the app at [http://localhost:3000](http://localhost:3000).
+
+### Build
+
+```bash
+npm run build
+```
+
+### Test
+
+```bash
+npm test
+```
+
+## Project Structure
+
+```
+src/
+  App.tsx              # App root, Apollo Client and Web3Modal setup
+  Chain.tsx            # Chain selector (Polygon / Solana / Tron)
+  Swap.tsx             # Swap form and order creation
+  Order.tsx            # Order tracking and Lightning invoice display
+  Connect.tsx          # Solana wallet connection provider
+  PolygonAddress.tsx   # Polygon wallet integration
+  SolAddress.tsx       # Solana wallet integration
+  constants.ts         # GraphQL mutations and chain enums
+```