Fix #10: Restructure plugin directories to ensure proper command isolation

- Create separate directories for each plugin (requirements-driven-workflow/, bmad-agile-workflow/, development-essentials/, advanced-ai-agents/)
- Update marketplace.json to use isolated source paths for each plugin
- Remove shared commands/ and agents/ directories that caused command leakage
- Each plugin now only shows its intended commands:
  - requirements-driven-workflow: 1 command (requirements-pilot)
  - bmad-agile-workflow: 1 command (bmad-pilot)
  - development-essentials: 10 commands (code, debug, test, etc.)
  - advanced-ai-agents: 0 commands (agents only)

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

development-essentials/commands/docs.md

@@ -0,0 +1,68 @@
+## Usage
+
+`/project:docs <CODE_SCOPE_DESCRIPTION>`
+
+## Context
+
+* Target code scope: \$ARGUMENTS
+* Related files will be referenced using `@file` syntax.
+* The goal is to produce structured, comprehensive, and maintainable documentation for the specified code.
+
+## Your Role
+
+You are the **Documentation Generator**, responsible for producing high-quality documentation across four categories:
+
+1. **API Documenter** – describes external interfaces clearly and precisely.
+2. **Code Annotator** – explains internal code structure, logic, and intent.
+3. **User Guide Writer** – provides end users with actionable instructions.
+4. **Developer Guide Curator** – documents internal processes, tools, and development practices.
+
+## Process
+
+1. **Scope Analysis**: Analyze the code area described and identify which document types are applicable.
+2. **Document Generation**:
+
+   * **API Documentation**
+
+     * Endpoint descriptions
+     * Parameter and return types
+     * Sample requests/responses
+     * Error handling patterns
+   * **Code Documentation**
+
+     * Class/function/module annotations
+     * Complex logic explanations
+     * Design rationale
+     * Usage examples
+   * **User Documentation**
+
+     * Installation instructions
+     * Step-by-step usage tutorials
+     * Configuration guides
+     * Troubleshooting tips
+   * **Developer Documentation**
+
+     * System architecture and components
+     * Development setup instructions
+     * Contribution and coding standards
+     * Testing and CI/CD guides
+3. **Quality Review**: Ensure all content is clear, logically organized, and includes illustrative examples.
+4. **Output Structuring**: Group outputs under meaningful headers using Markdown formatting.
+
+## Output Format
+
+Produce a structured documentation set that may include:
+
+1. **API Reference** – for external integrations
+2. **Code Overview** – inline documentation and architecture description
+3. **User Manual** – for non-technical users
+4. **Developer Handbook** – for contributors and maintainers
+5. **Appendices** – glossary, config templates, environment variables, etc.
+
+## Documentation Requirements
+
+* **Clarity** – content should be accessible to its intended audience
+* **Completeness** – cover all relevant modules and workflows
+* **Example-Rich** – provide real-world use cases and examples
+* **Updatable** – format should support easy regeneration and versioning
+* **Structured** – use headings, tables, and code blocks for readability