docs: build: add link to fedora cuda build guide

Author: teihome

docs/build.md

@@ -127,6 +127,8 @@ For detailed info, please refer to [llama.cpp for SYCL](./backend/SYCL.md).
 
 This provides GPU acceleration using an NVIDIA GPU. Make sure to have the CUDA toolkit installed. You can download it from your Linux distro's package manager (e.g. `apt install nvidia-cuda-toolkit`) or from the [NVIDIA developer site](https://developer.nvidia.com/cuda-downloads).
 
+If you are using Fedora, or would like to set up CUDA in a toolbox, please consider our [Fedora CUDA guide](./fedora-cuda.md). Unfortunately, the process is not as simple as one might expect.
+
 - Using `CMake`:
 
   ```bash