Feature: Help Topics System

[mphstudios]

Adds long-form documentation to the CLI via the help command.

Purpose

Users need guidance on workflows, troubleshooting, and feature-specific topics that do not fit in command help text. The Quire CLI needed extended documentation, beyond scope of the Commander.js built-in --help output.

Requirements for extended documentation:

• Display markdown-formatted help content (in the terminal)
• List available topics with a short description
• Page long content in interactive terminals
• Throw typed errors for unknown topics

Architecture Decisions

1. Use the existing help command to delegate to a "help content library"
2. The "help content library" should be versioned in the repository (lib/help/topics/) and maintained as part of code change and review process
3. Leverage the already installed js-yaml library for markdown files with YAML front-matter
4. Implement the "help content library" (lib/help/index.js) with a simple API that provides methods to getTopicList and getTopicContent
5. Implement a pager utility (helpers/pager.js) for long content (this should respect the system $PAGER environment setting)

❯ quire help           
Available help topics:

  configuration    Project and CLI configuration options
  debugging        Troubleshooting common issues
  epub             Creating e-book publications
  pdf              Creating print-ready PDF publications
  publishing       Deploying your Quire publication
  workflows        Step-by-step guides for common Quire tasks

Run "quire help <topic>" for detailed information.
Run "quire <command> --help" for command-specific options.

Content for topics is maintained as markdown files in the repository cli/src/lib/help/topics/ directory.

See the Help Topic System documentation included with this pull-request.