feat(showcase): add cortex device list documentation

- Introduced a new markdown file for the Cortex Device List, detailing its features, technical stack, and providing an overview of the application designed for browsing Neural DSP Quad Cortex devices.

content/showcase/cortex-device-list/index.md

@@ -0,0 +1,33 @@
+---
+title: "Cortex Device List"
+description: "A user-friendly interface for browsing and filtering Neural DSP Quad Cortex virtual devices and amp models."
+date: 2024-02-15
+showcase_categories: ["apps"]
+github: "your-username/cortex-device-list"
+demo: "https://www.quadcortex.co/"
+---
+
+## Overview
+
+Cortex Device List is an intuitive web application built with Aurelia 2 that provides a streamlined way to explore and filter through the extensive collection of virtual devices available on the Neural DSP Quad Cortex amp modeler. The app helps musicians and audio engineers quickly find the perfect amp, cabinet, or effect for their sound.
+
+## Features
+
+- **Comprehensive Device Browser**:
+  - Complete catalog of Quad Cortex virtual devices
+  - Real-time search and filtering
+  - Detailed device specifications and descriptions
+
+- **Smart Filtering System**:
+  - Filter by device type (amp, cabinet, effect)
+  - Category-based organization
+  - Manufacturer filtering
+  - Era/vintage filtering
+
+## Technical Stack
+
+- **Frontend**: Aurelia 2 with TailwindCSS
+- **State Management**: Built-in Aurelia state management
+- **Data Storage**: Local JSON database
+- **Search Engine**: Custom-built search indexing
+