Proposal: distribute as a Claude Code plugin marketplace

[te19oishi]

Summary

Add .claude-plugin/marketplace.json so the repo can be installed via /plugin marketplace add greptileai/skills instead of the current git clone + symlink dance.

Motivation

The current install instructions require users to:

1. git clone the repo into a specific path
2. Manually create symlinks for each sub-skill so Claude Code can discover them at the expected depth

This works but has friction:

• New users hit the symlink step without context (it exists because Claude Code looks for ~/.claude/skills/<name>/SKILL.md, and this is a multi-skill repo)
• Updates require git pull from the cloned location — no built-in update flow
• No discoverability beyond the README

Claude Code's plugin marketplace solves all three: one command to add the marketplace, one command per skill to install, and /plugin update for upgrades.

Proposed structure

Per the marketplace docs, each skill becomes its own plugin entry, with SKILL.md living under <plugin>/skills/<plugin>/SKILL.md:

skills/ (repo root)
├── .claude-plugin/
│   └── marketplace.json
├── check-pr/
│   ├── .claude-plugin/plugin.json
│   └── skills/check-pr/SKILL.md
└── greploop/
    ├── .claude-plugin/plugin.json
    └── skills/greploop/SKILL.md

marketplace.json would list both skills:

{
  "name": "greptile",
  "owner": { "name": "Greptile" },
  "plugins": [
    { "name": "check-pr", "source": "./check-pr", "description": "..." },
    { "name": "greploop", "source": "./greploop", "description": "..." }
  ]
}

User-facing install becomes:

/plugin marketplace add greptileai/skills
/plugin install check-pr@greptile
/plugin install greploop@greptile

Open questions before I send a PR

1. Backward compatibility — keep the clone+symlink instructions in the README as a fallback, or drop them once the plugin path lands?
2. Marketplace name — greptile vs. greptile-skills vs. something else? Affects the install command (@greptile suffix).
3. File moves — the restructure moves check-pr/SKILL.md → check-pr/skills/check-pr/SKILL.md (same for greploop). Happy to do this in a single PR, but flagging that it's a non-trivial diff for reviewers. Would you prefer it split (one PR per skill)?
4. Scope — anything else you'd want bundled into this change (e.g. CI to validate marketplace.json)?

Happy to open the PR once there's directional alignment. Wanted to avoid the fate of #4 by checking first.