feat: Add VitePress docs, EPUB to PDF tool, Phosphor icons, and licensing updates

- Set up VitePress documentation site (docs:dev, docs:build, docs:preview)
- Added Getting Started, Tools Reference, Contributing, and Commercial License pages
- Created self-hosting guides for Docker, Vercel, Netlify, Cloudflare, AWS, Hostinger, Nginx, Apache
- Updated README with documentation link, sponsors section, and docs contribution guide

- Added EPUB to PDF converter using LibreOffice WASM

- Migrated to Phosphor Icons for consistent iconography

- Added donation ribbon banner on landing page
- Removed 'Like My Work?' section (replaced by ribbon)
- Updated licensing.html with delivery model, AGPL notice, invoicing, and no-refund policy

- Added Commercial License documentation page
- Updated translations table (Chinese added, marked non-English as In Progress)

- Added sponsors.yml workflow for auto-generating sponsor avatars

docs/contributing.md

@@ -0,0 +1,136 @@
+# Contributing
+
+Thank you for your interest in contributing to BentoPDF! This guide will help you get started.
+
+## Getting Started
+
+### Prerequisites
+
+- Node.js 18+
+- npm 9+
+- Git
+
+### Setup
+
+```bash
+# Fork and clone the repository
+git clone https://github.com/YOUR_USERNAME/bentopdf.git
+cd bentopdf
+
+# Install dependencies
+npm install
+
+# Start development server
+npm run dev
+```
+
+## Project Structure
+
+```
+bentopdf/
+├── src/
+│   ├── js/
+│   │   ├── config/       # Tool definitions
+│   │   ├── logic/        # Tool page logic
+│   │   ├── utils/        # Shared utilities
+│   │   └── ui.ts         # UI helpers
+│   ├── pages/            # Tool HTML pages
+│   └── css/              # Styles
+├── public/
+│   ├── locales/          # Translations
+│   └── pymupdf-wasm/     # WASM modules
+├── docs/                 # Documentation (VitePress)
+└── scripts/              # Build scripts
+```
+
+## Adding a New Tool
+
+### Step 1: Create the Logic File
+
+Create `src/js/logic/your-tool-page.ts`:
+
+```typescript
+import { showLoader, hideLoader, showAlert } from '../ui.js';
+import { state } from '../state.js';
+
+document.addEventListener('DOMContentLoaded', () => {
+    // Your tool logic here
+});
+```
+
+### Step 2: Create the HTML Page
+
+Create `src/pages/your-tool.html` following the existing tool templates.
+
+### Step 3: Register the Tool
+
+Add to `src/js/config/tools.ts`:
+
+```typescript
+{
+  href: import.meta.env.BASE_URL + 'your-tool.html',
+  name: 'Your Tool',
+  icon: 'ph-icon-name',
+  subtitle: 'Description of your tool.',
+}
+```
+
+### Step 4: Add to Build Config
+
+Add the page to `vite.config.ts`:
+
+```typescript
+'your-tool': resolve(__dirname, 'src/pages/your-tool.html'),
+```
+
+### Step 5: Add Translations
+
+Add entries to all locale files in `public/locales/`:
+
+```json
+{
+  "yourTool": {
+    "name": "Your Tool",
+    "subtitle": "Description"
+  }
+}
+```
+
+## Code Style
+
+- Use TypeScript for all new code
+- Follow existing patterns for consistency
+- Run `npm run format` before committing
+- No comments in production code (comments removed during build)
+
+## Pull Request Process
+
+1. Create a feature branch: `git checkout -b feature/your-feature`
+2. Make your changes
+3. Test thoroughly: `npm run build`
+4. Submit a PR with a clear description
+
+## Translation
+
+See [TRANSLATION.md](https://github.com/bentopdf/bentopdf/blob/main/TRANSLATION.md) for adding new languages.
+
+## Contributor License Agreement
+
+Before your PR can be merged, you'll need to sign our CLA:
+
+- [Individual CLA (ICLA)](https://github.com/bentopdf/bentopdf/blob/main/ICLA.md)
+- [Corporate CLA (CCLA)](https://github.com/bentopdf/bentopdf/blob/main/CCLA.md)
+
+## Getting Help
+
+- [GitHub Issues](https://github.com/bentopdf/bentopdf/issues)
+- [Discord Community](https://discord.gg/Bgq3Ay3f2w)
+
+## License
+
+BentoPDF is dual-licensed:
+
+- **AGPL-3.0** for open-source projects where you share your full source code publicly
+- **Commercial License** for proprietary/closed-source applications - [Get Lifetime License for $49](https://ko-fi.com/s/f32ca4cb75)
+
+By contributing, you agree that your contributions will be licensed under these terms.