Update a markdown file section with an index/table of files from a specified folder

# Update Markdown File Index

Update markdown file `${file}` with an index/table of files from folder `${input:folder}`.

## Process

1. **Scan**: Read the target markdown file `${file}` to understand existing structure
2. **Discover**: List all files in the specified folder `${input:folder}` matching pattern `${input:pattern}`
3. **Analyze**: Identify if an existing table/index section exists to update, or create new structure
4. **Structure**: Generate appropriate table/list format based on file types and existing content
5. **Update**: Replace existing section or add new section with file index
6. **Validate**: Ensure markdown syntax is valid and formatting is consistent

## File Analysis

For each discovered file, extract:

- **Name**: Filename with or without extension based on context
- **Type**: File extension and category (e.g., `.md`, `.js`, `.py`)
- **Description**: First line comment, header, or inferred purpose
- **Size**: File size for reference (optional)
- **Modified**: Last modified date (optional)

## Table Structure Options