fix: [DOCS] Plugin .mcp.json example incorrectly uses mcpServers wrapper - #64607

Summary

Root Cause

The .mcp.json examples in the plugin documentation incorrectly wrapped server entries in a mcpServers key. The mcpServers key is a plugin.json manifest concept (used to point to an external file or define servers inline). The .mcp.json file itself uses a flat format where server names are top-level keys — consistent with all official plugins in anthropics/claude-plugins-official.

Change Made

Fixed two files that showed .mcp.json examples with the incorrect mcpServers wrapper:

1. plugins/plugin-dev/skills/plugin-structure/SKILL.md (line ~242):
   Removed the mcpServers wrapper from the "Example format" code block under "MCP Servers".

2. plugins/plugin-dev/skills/plugin-structure/examples/advanced-plugin.md (line ~148):
   Removed the mcpServers wrapper from the .mcp.json section of the advanced plugin example (kubernetes, terraform, github-actions servers).

Both changes convert the examples from:

{
  "mcpServers": {
    "server-name": { ... }
  }
}

to the correct flat format:

{
  "server-name": { ... }
}

Issue

Fixes #63694

Issue URL: #63694

Changes

.../plugin-dev/skills/plugin-structure/SKILL.md    | 12 +++---
 .../plugin-structure/examples/advanced-plugin.md   | 46 +++++++++++-----------
 2 files changed, 27 insertions(+), 31 deletions(-)

Testing

• Agent ran relevant tests during development

• Linting checks passed

• Changes are minimal and focused on the issue

AI Assistance Disclosure

This pull request was prepared with the assistance of AI coding tools (GitHub Copilot). The change has been read, understood, and is owned by the human contributor submitting it, who will respond to review feedback.