Documentation Generation Skill

Create comprehensive documentation for projects.

1. README Templates

Basic README:

# Project Name

Brief description of what this project does.

## Installation

\`\`\`bash
npm install
# or
pip install -r requirements.txt
\`\`\`

## Usage

\`\`\`bash
npm start
# or
python app.py
\`\`\`

## Features

- Feature 1
- Feature 2
- Feature 3

## Configuration

Environment variables:
- `API_KEY` - Your API key
- `DATABASE_URL` - Database connection string

## Contributing

Pull requests are welcome.

## License

MIT

2. API Documentation

OpenAPI/Swagger:

openapi: 3.0.0
info:
  title: My API
  version: 1.0.0
paths:
  /users:
    get:
      summary: List users
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/User'
components:
  schemas:
    User:
      type: object
      properties:
        id:
          type: integer
        name:
          type: string
        email:
          type: string

3. Code Comments

Python Docstrings:

def calculate_total(items, tax_rate=0.08):
    """
    Calculate total price including tax.

    Args:
        items (list): List of items with price and quantity
        tax_rate (float, optional): Tax rate. Defaults to 0.08.

    Returns:
        float: Total price including tax

    Raises:
        ValueError: If items is empty or tax_rate is negative

    Example:
        >>> items = [{'price': 10, 'qty': 2}]
        >>> calculate_total(items)
        21.6
    """
    if not items:
        raise ValueError("Items cannot be empty")
    if tax_rate < 0:
        raise ValueError("Tax rate cannot be negative")

    subtotal = sum(item['price'] * item['qty'] for item in items)
    return subtotal * (1 + tax_rate)

JavaScript JSDoc:

/**
 * Calculate total price including tax
 * @param {Array<{price: number, qty: number}>} items - Items to calculate
 * @param {number} [taxRate=0.08] - Tax rate
 * @returns {number} Total price including tax
 * @throws {Error} If items is empty
 * @example
 * const items = [{price: 10, qty: 2}];
 * calculateTotal(items); // 21.6
 */
function calculateTotal(items, taxRate = 0.08) {
    if (!items.length) {
        throw new Error("Items cannot be empty");
    }
    const subtotal = items.reduce((sum, item) =>
        sum + item.price * item.qty, 0);
    return subtotal * (1 + taxRate);
}

4. Architecture Documentation

# Architecture

## Overview

System consists of three main components:
- Frontend (React)
- Backend API (Node.js)
- Database (PostgreSQL)

## Components

### Frontend
- React SPA
- Redux for state management
- Material-UI components

### Backend
- Express.js REST API
- JWT authentication
- PostgreSQL database

### Database Schema

\`\`\`sql
users (id, email, password_hash, created_at)
orders (id, user_id, total, status, created_at)
\`\`\`

## Data Flow

1. User makes request
2. Frontend sends API call
3. Backend validates and processes
4. Database updated
5. Response returned to frontend

5. Generate Docs from Code

Python (Sphinx):

# Install
pip install sphinx

# Initialize
sphinx-quickstart docs

# Generate
cd docs
make html

JavaScript (JSDoc):

# Install
npm install -g jsdoc

# Generate
jsdoc src/ -d docs/

6. Changelog

# Changelog

## [1.2.0] - 2026-01-22

### Added
- New user authentication feature
- CSV export functionality

### Changed
- Improved performance of search
- Updated UI design

### Fixed
- Bug in payment processing
- XSS vulnerability in comments

### Removed
- Deprecated API endpoint /old-users

When to Use This Skill

Use /docs for generating documentation, API specs, README files, and code comments.