Update Context7 plugin for v2 API

- Update skill/agent/command to use new query-docs tool (replaces get-library-docs)
- Add query parameter usage for intelligent reranking
- Add version pinning support (e.g., /vercel/next.js/v15.1.8)
- Add tools and model metadata to agent
- Simplify docs to focus on workflow, not parameter details
- Add README.md with usage examples

external_plugins/context7/.claude-plugin/plugin.json

@@ -2,6 +2,6 @@
   "name": "context7",
   "description": "Upstash Context7 MCP server for up-to-date documentation lookup. Pull version-specific documentation and code examples directly from source repositories into your LLM context.",
   "author": {
-    "name": "Upstash"
+    "name": "Upstash "
   }
 }