Add CONTRIBUTION.md with guidelines for contributors (#147)

* Add CONTRIBUTION.md with guidelines for contributors

* Adding the discord link

* Adding proper steps for running locally , removing the test area , adding the correct link for discord

CONTRIBUTION.md

@@ -0,0 +1,204 @@
+# 🤝 Contributing to Unsend
+
+Thanks for your interest in contributing to **Unsend**! We’re an open-source email infrastructure platform, and we’d love your help to make it even better. This guide will walk you through how to get started, set up the project locally, and submit contributions.
+
+---
+
+## 🧰 Getting Started
+
+All contributions begin with setting up the project locally. Follow the steps below to get started.
+
+📖 **Refer to the full setup guide:**  
+[https://docs.unsend.dev/get-started/local](https://docs.unsend.dev/get-started/local)
+
+### ⚙️ Prerequisites
+
+You’ll need:
+
+- A GitHub account
+- Node.js v18+
+- `pnpm` (use `corepack enable` to activate)
+- Docker (recommended)
+- AWS & Cloudflare accounts (free tiers are fine)
+
+---
+
+## 🛠 Setting Up the Project
+
+### 1. Fork & Clone
+
+```bash
+git clone https://github.com/YOUR-USERNAME/unsend.git
+cd unsend
+```
+
+### 2. Install Dependencies
+
+```bash
+corepack enable
+pnpm install
+```
+
+### 3. Setup Environment Variables
+
+```bash
+cp .env.example .env
+```
+
+Then:
+
+- Generate a secret:
+
+```bash
+openssl rand -base64 32
+```
+
+- Add this to `.env` as `NEXTAUTH_SECRET`.
+
+### 4. GitHub OAuth (Optional for Dev)
+
+Set up a GitHub OAuth App:  
+- Homepage: `http://localhost:3000/login`  
+- Callback: `http://localhost:3000/api/auth/callback/github`
+
+Add credentials to `.env`:
+
+```env
+GITHUB_ID=your_client_id
+GITHUB_SECRET=your_client_secret
+```
+
+### 5. AWS Credentials (Optional for local email)
+
+If you want to send real emails, add:
+
+```env
+AWS_ACCESS_KEY=your_access_key
+AWS_SECRET_KEY=your_secret_key
+```
+
+> You can skip this by using the `local-sen-sns` image for local-only email development.
+
+---
+
+## 🚀 Running the App
+
+### Option 1: Docker (Recommended)
+
+```bash
+pnpm d
+```
+
+- **Dashboard**: [http://localhost:3000](http://localhost:3000)  
+- **Marketing Site**: [http://localhost:3001](http://localhost:3001)
+
+> To test GitHub login, run:
+
+```bash
+cloudflared tunnel --url http://localhost:3000
+```
+
+Paste the Cloudflare URL in your GitHub App callback settings.
+
+---
+
+### Option 2: Manual DB Setup
+
+If you're using your own PostgreSQL & Redis:
+
+1. Add in `.env`:
+
+```env
+DATABASE_URL=your_postgres_url
+REDIS_URL=your_redis_url
+```
+
+2. Migrate database:
+
+```bash
+pnpm db:migrate-dev
+```
+
+3. Start dev server:
+
+```bash
+pnpm dev
+```
+
+4. Use `cloudflared` as mentioned above if needed.
+
+---
+
+### 📝 Run Documentation Locally
+
+```bash
+pnpm dev:docs
+```
+
+---
+
+## 📂 Code Structure Overview
+
+```
+apps/
+├── web          # Dashboard & Email Infra
+├── marketing    # Landing page
+├── docs         # This documentation site
+
+packages/
+├── eslint-config     # Shared ESLint rules
+├── sdk               # TypeScript SDK for Unsend REST API
+├── tailwind-config   # Shared Tailwind setup
+├── typescript-config # Shared tsconfig
+├── ui                # Shared UI components (buttons, modals, etc.)
+```
+
+---
+
+## 🧑‍💻 Making Contributions
+
+1. **Create a Feature Branch**
+
+```bash
+git checkout -b feat/your-feature
+```
+
+2. **Make Your Changes**
+   - Follow the existing project structure.
+   - Write clean, modular, and reusable code.
+   - Formatting is enforced with Prettier.
+
+3. **Commit Your Work**
+
+```bash
+git add .
+git commit -m "feat: your message here"
+```
+
+4. **Push and Open a Pull Request**
+
+```bash
+git push origin feat/your-feature
+```
+
+- Open a PR against the `main` branch
+- Fill in the PR template
+
+---
+
+## 💬 Community and Support
+
+- **Discord**: [Join our server](https://discord.gg/BU8n8pJv8S)
+- **GitHub Discussions**: [Start a discussion](https://github.com/unsend-dev/unsend/discussions)
+- **GitHub Issues**: [Report issues or bugs](https://github.com/unsend-dev/unsend/issues)
+
+---
+
+## 🙋 Questions?
+
+Need help or unsure where to begin? Just ask!
+
+- Chat with us on [Discord](https://discord.gg/BU8n8pJv8S)
+- Open an [Issue](https://github.com/unsend-dev/unsend/issues)
+
+We’re excited to see your ideas and contributions! 💌