Update README with API documentation and usage examples

Author: ckeyer

README.md

@@ -1,20 +1,172 @@
 # InkForge
-InkForge is a high-performance Markdown rendering engine designed for developers and AI systems. It converts Markdown content into high-quality image outputs with full support for standard Markdown syntax, LaTeX mathematical expressions (powered by KaTeX), and Mermaid diagrams including flowcharts and sequence diagrams.
 
-Built on a browser-level rendering pipeline, InkForge ensures consistent layout, pixel-perfect output, and cross-platform compatibility. It is ideal for AI-generated reports, knowledge base exports, automated documentation pipelines, and dynamic content cards.
+InkForge is a high-performance Markdown rendering engine designed for developers and AI systems. It converts Markdown content into high-quality image outputs with full support for standard Markdown syntax, LaTeX mathematical expressions (powered by KaTeX), syntax highlighting (powered by Prism), and Mermaid diagrams.
 
-The system supports high-concurrency deployment, browser pooling optimization, and containerized environments, making it suitable as an infrastructure component within AI agents or model platforms.
+Built on a browser-level rendering pipeline using Playwright, InkForge ensures consistent layout, pixel-perfect output, and cross-platform compatibility.
 
-Key features include:
+## Features
 
-✅ Markdown to PNG / JPG / WebP
+- **Markdown to Image** - Convert Markdown to PNG, JPEG, or WebP
+- **LaTeX Math** - Full support for inline and display math equations using KaTeX
+- **Syntax Highlighting** - Code blocks with syntax highlighting (Python, JavaScript, TypeScript, Go, Bash, etc.)
+- **Mermaid Diagrams** - Flowcharts, sequence diagrams, and more
+- **Theme Support** - Light and dark themes
+- **High Resolution** - Configurable scale factor for retina-quality output
+- **API-First** - Easy integration via REST API
 
-✅ Advanced mathematical formula rendering
+## Quick Start
 
-✅ Mermaid diagram support
+### Run with Docker
 
-✅ High-resolution and theme customization
+```bash
+docker run -d -p 8080:8080 insmtx/inkforge
+```
 
-✅ API-first microservice architecture
+### Run from Source
 
-InkForge aims to serve as a foundational document-to-visual rendering engine for the AI era.
+```bash
+# Install dependencies
+go mod download
+
+# Build
+go build -o inkforge ./cmd/inkforge/
+
+# Run
+./inkforge
+```
+
+The server will start at `http://localhost:8080`
+
+## Demo
+
+Open `http://localhost:8080` in your browser to access the interactive demo page.
+
+## API Usage
+
+### Convert Markdown to Image
+
+**Endpoint:** `POST /api/v1/markdown2image`
+
+**Request:**
+
+```json
+{
+  "content": "# Hello World\n\nThis is **bold** and *italic* text.",
+  "title": "My Document",
+  "theme": "light",
+  "image_format": "png",
+  "width": 1200,
+  "height": 800,
+  "scale": 2.0
+}
+```
+
+**Response:**
+
+```json
+{
+  "status": "success",
+  "image_data": "<base64-encoded-image>",
+  "image_format": "png",
+  "size": {
+    "width": 1200,
+    "height": 800
+  },
+  "duration_ms": 1500
+}
+```
+
+### cURL Example
+
+```bash
+curl -X POST http://localhost:8080/api/v1/markdown2image \
+  -H "Content-Type: application/json" \
+  -d '{
+    "content": "# Hello\n\n$$E=mc^2$$",
+    "title": "Math Test",
+    "image_format": "png"
+  }' \
+  --output output.png
+```
+
+### Generate HTML (Debug)
+
+**Endpoint:** `POST /api/v1/generatehtml`
+
+Returns the generated HTML for debugging purposes.
+
+### Health Check
+
+**Endpoint:** `GET /api/v1/health`
+
+Returns `{"status": "ok"}` when the service is running.
+
+## Request Parameters
+
+| Parameter | Type | Default | Description |
+|-----------|------|---------|-------------|
+| content | string | required | Markdown content to convert |
+| title | string | "" | Document title |
+| theme | string | "light" | Theme: "light" or "dark" |
+| image_format | string | "png" | Output format: "png", "jpg", "webp" |
+| width | int | 1200 | Image width in pixels |
+| height | int | 800 | Image height in pixels |
+| scale | float | 2.0 | Scale factor for high-DPI (2.0 = 2x) |
+| quality | int | 90 | JPEG/WebP quality (1-100) |
+| css | string | "" | Custom CSS styles |
+
+## Supported Markdown Features
+
+### Code Blocks
+
+````markdown
+```python
+def hello():
+    print("Hello!")
+```
+````
+
+Supported languages: Python, JavaScript, TypeScript, Go, Bash, JSON, and more.
+
+### Math Equations
+
+Inline: `$E=mc^2$`
+
+Display:
+```
+$$
+\int_0^\infty e^{-x^2} dx = \frac{\sqrt{\pi}}{2}
+$$
+```
+
+### Mermaid Diagrams
+
+````markdown
+```mermaid
+graph TD
+    A[Start] --> B{Decision}
+    B -->|Yes| C[Process]
+    B -->|No| D[End]
+```
+````
+
+### Tables
+
+````markdown
+| Column 1 | Column 2 |
+|----------|----------|
+| Cell 1   | Cell 2   |
+````
+
+## Architecture
+
+- **Gin** - Web framework
+- **Playwright** - Browser-based rendering
+- **KaTeX** - LaTeX math rendering
+- **Prism** - Syntax highlighting
+- **Mermaid** - Diagram rendering
+- **gomarkdown** - Markdown parsing
+
+## License
+
+MIT License - see LICENSE file for details.