docs(claude-design): add Table of Contents to README

Flat H2-only list, placed after the intro paragraph before Install.
Anchors machine-validated against actual headings (16/16 match,
zero dead links); a deliberately broken anchor confirmed the check
fires before trusting the clean run.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018mi5sCfmJKdePnSZ6dKUDo

README.md

@@ -4,6 +4,24 @@ End-to-end facilitator for prompting Claude Design (claude.ai/design) — idea t
 
 A Claude Code plugin that ships one skill (`claude-design-facilitator`) plus a reference tree for prompting Anthropic's `claude.ai/design` workspace. The skill auto-fires on natural-language triggers, walks the operator through an eight-phase facilitation flow, and produces a prompt grounded in Anthropic's verbatim Goal / Layout / Content / Audience framework and the published per-preset prompt patterns. For anyone who keeps getting the convergent default aesthetic back from Claude Design. Output is the prompt — the artifact gets built in Claude Design.
 
+## Table of Contents
+
+- [Install](#install)
+- [Requirements](#requirements)
+- [Why this exists](#why-this-exists)
+- [Scope and complementarity](#scope-and-complementarity)
+- [Non-goals](#non-goals)
+- [What you can do with it](#what-you-can-do-with-it)
+- [Workflow example: from idea to prompt](#workflow-example-from-idea-to-prompt)
+- [Skill surface](#skill-surface)
+- [Reference content map](#reference-content-map)
+- [Per-preset coverage](#per-preset-coverage)
+- [Verification](#verification)
+- [Compatibility](#compatibility)
+- [Re-research triggers](#re-research-triggers)
+- [Changelog](#changelog)
+- [License](#license)
+
 ## Install
 
 Add the marketplace once, then install the plugin: