Update documentation to include VS Code extension

- Add VS Code platform to repository structure in development docs
- Add section on developing the VS Code extension
- Update main README with platforms section
- Link to platform-specific documentation

Co-authored-by: mikebarkmin <2592379+mikebarkmin@users.noreply.github.com>

Author: Copilot

README.md

@@ -9,6 +9,13 @@ explore learning pathways. It is developed by
 - **Repository:** https://github.com/openpath/learningmap
 - **Community**: https://matrix.to/#/#openpatch:matrix.org
 
+## Platforms
+
+- **Web App**: Create and share learningmaps at [learningmap.app](https://learningmap.app)
+- **VS Code Extension**: Edit `.learningmap` files locally in VS Code (see [platforms/vscode](platforms/vscode))
+- **React Component**: Integrate learningmap into your own React app (see [packages/learningmap](packages/learningmap))
+- **Web Component**: Use learningmap in any web application (see [packages/web-component](packages/web-component))
+
 ## Documentation
 
 If you want to work on the documentation, run the

docs/book/development.md

@@ -40,7 +40,8 @@ learningmap/
 │   ├── learningmap/          # Core React component library
 │   └── web-component/        # Web component wrapper
 ├── platforms/
-│   └── web/                  # Web application (learningmap.app)
+│   ├── web/                  # Web application (learningmap.app)
+│   └── vscode/               # VS Code extension
 ├── docs/                     # Documentation (Hyperbook)
 └── scripts/                  # Build and development scripts
 ```
@@ -88,6 +89,23 @@ pnpm docs:dev
 
 The documentation is built with [Hyperbook](https://hyperbook.openpatch.org) and is located in the `docs/` directory.
 
+### VS Code Extension
+
+To develop the VS Code extension:
+
+1. Build the extension:
+   ```bash
+   pnpm --filter learningmap-vscode build
+   ```
+
+2. Open the `platforms/vscode` directory in VS Code
+
+3. Press F5 to launch the Extension Development Host
+
+4. Open or create a `.learningmap` file to test the editor
+
+See [platforms/vscode/DEVELOPMENT.md](../../platforms/vscode/DEVELOPMENT.md) for more details.
+
 ## Testing Your Changes
 
 1. **Type-check**: `pnpm lint`