chore(docs): add documentation on backend detection override (#5915)

Signed-off-by: Ettore Di Giacinto <[email protected]>

Author: mudler

README.md

@@ -189,6 +189,8 @@ local-ai run https://gist.githubusercontent.com/.../phi-2.yaml
 local-ai run oci://localai/phi-2:latest
 ```
 
+> ⚡ **Automatic Backend Detection**: When you install models from the gallery or YAML files, LocalAI automatically detects your system's GPU capabilities (NVIDIA, AMD, Intel) and downloads the appropriate backend. For advanced configuration options, see [GPU Acceleration](https://localai.io/features/gpu-acceleration/#automatic-backend-detection).
+
 For more information, see [💻 Getting started](https://localai.io/basics/getting_started/index.html)
 
 ## 📰 Latest project news

docs/content/docs/features/GPU-acceleration.md

@@ -15,6 +15,16 @@ This section contains instruction on how to use LocalAI with GPU acceleration.
 For acceleration for AMD or Metal HW is still in development, for additional details see the [build]({{%relref "docs/getting-started/build#Acceleration" %}})
 {{% /alert %}}
 
+## Automatic Backend Detection
+
+When you install a model from the gallery (or a YAML file), LocalAI intelligently detects the required backend and your system's capabilities, then downloads the correct version for you. Whether you're running on a standard CPU, an NVIDIA GPU, an AMD GPU, or an Intel GPU, LocalAI handles it automatically.
+
+For advanced use cases or to override auto-detection, you can use the `LOCALAI_FORCE_META_BACKEND_CAPABILITY` environment variable. Here are the available options:
+
+- `default`: Forces CPU-only backend. This is the fallback if no specific hardware is detected.
+- `nvidia`: Forces backends compiled with CUDA support for NVIDIA GPUs.
+- `amd`: Forces backends compiled with ROCm support for AMD GPUs.
+- `intel`: Forces backends compiled with SYCL/oneAPI support for Intel GPUs.
 
 ## Model configuration
 

docs/content/docs/getting-started/quickstart.md

@@ -106,6 +106,9 @@ local-ai run https://gist.githubusercontent.com/.../phi-2.yaml
 local-ai run oci://localai/phi-2:latest
 ```
 
+{{% alert icon="⚡" %}}
+**Automatic Backend Detection**: When you install models from the gallery or YAML files, LocalAI automatically detects your system's GPU capabilities (NVIDIA, AMD, Intel) and downloads the appropriate backend. For advanced configuration options, see [GPU Acceleration]({{% relref "docs/features/gpu-acceleration#automatic-backend-detection" %}}).
+{{% /alert %}}
 
 For a full list of options, refer to the [Installer Options]({{% relref "docs/advanced/installer" %}}) documentation.