Adds WLED app

[jcleigh]

This pull request adds a new documentation page for the WLED app, providing a comprehensive overview of its features, controls, installation steps, file layout, and configuration requirements. The documentation is structured to help users understand how to install, configure, and use the app to control WLED devices from their badge.

New WLED app documentation:

• Added a new markdown file src/content/apps/wled.mdx with a detailed description of the WLED controller app, including its features (status monitor, power toggle, color presets, effect picker, brightness control) and user controls.
• Included installation instructions and file layout to guide users through copying and setting up the app on their device.
• Provided configuration details for WiFi and WLED device IP in /secrets.py, ensuring users know how to connect their badge to a WLED device.
• Linked to the full source code for further reference and troubleshooting.

[Copilot]

Pull Request Overview

This PR adds comprehensive documentation for the WLED controller app, enabling users to control WLED lighting devices directly from their badge. The documentation follows the established app documentation pattern and includes all necessary setup and usage information.

Key changes:

• Added detailed WLED app documentation with features, controls, installation, and configuration
• Included icon asset for the app launcher
• Provided WiFi and device IP configuration examples

Reviewed Changes

Copilot reviewed 1 out of 2 changed files in this pull request and generated 4 comments.

File	Description
src/content/apps/wled.mdx	Complete documentation page for WLED controller app including features, multi-view controls, installation steps, file layout, and required secrets.py configuration
public/images/apps/wled_icon.png	PNG icon asset for the WLED app launcher