Enhance documentation for MLX backend support

docs/getting-started/installation.md

@@ -4,11 +4,14 @@ This guide will walk you through installing Llamactl on your system.
 
 ## Prerequisites
 
+### Backend Dependencies
+
+llamactl supports multiple backends. Install at least one:
+
+**For llama.cpp backend (all platforms):**
+
 You need `llama-server` from [llama.cpp](https://github.com/ggml-org/llama.cpp) installed:
 
-
-**Quick install methods:**
-
 ```bash
 # Homebrew (macOS/Linux)
 brew install llama.cpp
@@ -18,6 +21,22 @@ winget install llama.cpp
 
 Or build from source - see llama.cpp docs
 
+**For MLX backend (macOS only):**
+
+MLX provides optimized inference on Apple Silicon. Install MLX-LM:
+
+```bash
+# Install via pip (requires Python 3.8+)
+pip install mlx-lm
+
+# Or in a virtual environment (recommended)
+python -m venv mlx-env
+source mlx-env/bin/activate
+pip install mlx-lm
+```
+
+Note: MLX backend is only available on macOS with Apple Silicon (M1, M2, M3, etc.)
+
 ## Installation Methods
 
 ### Option 1: Download Binary (Recommended)