Claude Code plugin: bundle the Fizzdoc MCP server with a skill #59

Part of #57. Builds on the MCP server issue.

Goal

Make Fizzdoc installable as a Claude Code plugin, so that asking "merge these two PDFs" or "cut the first 30 seconds of this MP3" uses Fizzdoc's local tools instead of an upload or a throwaway script.

What the plugin contains

• The MCP server from the sibling issue, started with npx.
• A skill that tells the agent when to reach for Fizzdoc and how to use it:
  • which tool fits which request;
  • that files stay local;
  • page-range syntax;
  • where outputs are written.
• Optionally, a few slash commands for the most common jobs.
• A marketplace entry in this repository, so users can add it straight from GitHub.

Follow the current Claude Code plugin documentation for the file layout and manifest.

Done when

• The plugin installs from this repo following the steps in its README.
• In a fresh Claude Code session, "merge a.pdf and b.pdf" calls merge_pdf and writes merged.pdf next to the inputs.
• The README has a short "Use Fizzdoc in Claude Code" section.