Add skills and docs (#321)

* Add vscode files

* feat: Make repository AI-native with Agent Skills and comprehensive documentation

- Add AGENTS.md as main guide for AI coding agents (OpenHands, Claude Code)
- Create 7 Agent Skills in .agents/skills/ following Agent Skills standard:
  - add-ros2-package: Create new ROS 2 packages
  - integrate-module-into-layer: Integrate modules into bringup
  - write-isaac-sim-scene: Create Isaac Sim scenarios
  - debug-module: Autonomous debugging strategies
  - update-documentation: Documentation workflow
  - test-in-simulation: End-to-end simulation testing
  - add-behavior-tree-node: Create behavior tree nodes
- Add package template with C++/Python examples in skill assets
- Add system_architecture.md with mermaid diagrams showing data flow
- Add integration_checklist.md with standard topics and requirements
- Add ai_agent_guide.md as quick reference for agents
- Update mkdocs.yml with new documentation sections
- Convert CLAUDE.md to symlink to AGENTS.md

Enables AI agents to quickly understand repository structure, implement
features following established patterns, and autonomously debug and test.

* Delete old files

* Reorganize docs

* Update logo and paths

* Rename

* Update docs

* Improve docs and add docs skill

* Improve docs

* More docs

* Fix lists

* Improvements

* Fix paths

Author: andrewjong

.agents/README.md

@@ -0,0 +1,70 @@
+# AirStack Agent Skills
+
+This directory contains Agent Skills following the [Agent Skills standard](https://agentskills.io).
+
+## Structure
+
+```
+.agents/
+├── README.md           # This file
+└── skills/             # Agent Skills directory
+    ├── add-ros2-package/
+    │   └── SKILL.md    # Create new ROS 2 packages
+    ├── integrate-module-into-layer/
+    │   └── SKILL.md    # Integrate modules into layer bringup
+    ├── write-isaac-sim-scene/
+    │   └── SKILL.md    # Create Isaac Sim simulation scenes
+    ├── debug-module/
+    │   └── SKILL.md    # Autonomous debugging strategies
+    ├── update-documentation/
+    │   └── SKILL.md    # Document modules and update mkdocs
+    ├── test-in-simulation/
+    │   └── SKILL.md    # End-to-end simulation testing
+    └── add-behavior-tree-node/
+        └── SKILL.md    # Create behavior tree nodes
+```
+
+## Skills Overview
+
+Each skill is a directory containing a `SKILL.md` file with:
+- **YAML frontmatter:** Name, description, license, metadata
+- **Markdown body:** Step-by-step instructions for the workflow
+
+### Available Skills
+
+| Skill | Purpose |
+|-------|---------|
+| [add-ros2-package](skills/add-ros2-package) | Create a new ROS 2 package for the autonomy stack |
+| [integrate-module-into-layer](skills/integrate-module-into-layer) | Integrate a module into layer bringup |
+| [write-isaac-sim-scene](skills/write-isaac-sim-scene) | Create custom simulation environments |
+| [debug-module](skills/debug-module) | Systematically debug ROS 2 modules |
+| [update-documentation](skills/update-documentation) | Document modules and update mkdocs |
+| [test-in-simulation](skills/test-in-simulation) | Test modules in Isaac Sim |
+| [add-behavior-tree-node](skills/add-behavior-tree-node) | Create behavior tree nodes |
+
+## Usage
+
+Skills are designed for AI coding agents (OpenHands, Claude Code, etc.) to:
+
+1. **Discover** skills through the description field
+2. **Activate** relevant skill when task matches
+3. **Follow** step-by-step instructions in SKILL.md
+4. **Reference** cross-linked skills for related workflows
+
+## For Developers
+
+When adding new skills:
+
+1. Create directory with hyphenated name (e.g., `my-new-skill/`)
+2. Add `SKILL.md` with proper YAML frontmatter
+3. Follow Agent Skills format specification
+4. Reference related skills using relative paths (`../other-skill/`)
+5. Update this README with the new skill
+
+## References
+
+- **Main Guide:** [AGENTS.md](../AGENTS.md)
+- **Agent Skills Spec:** [https://agentskills.io](https://agentskills.io)
+- **System Architecture:** [docs/robot/autonomy/system_architecture.md](../docs/robot/autonomy/system_architecture.md)
+- **Integration Checklist:** [docs/robot/autonomy/integration_checklist.md](../docs/robot/autonomy/integration_checklist.md)
+- **AI Agent Guide:** [docs/development/ai_agent_guide.md](../docs/development/ai_agent_guide.md)