Adding the reference for the GPU guide

README.md

@@ -1,5 +1,5 @@
 # QFactor and QFactor-Sample Implementations on GPUs Using JAX
-`bqskit-qfactor-jax` is a Python package that implements circuit instantiation using the [QFactor](https://ieeexplore.ieee.org/abstract/document/10313638) and [QFactor-Sample](https://arxiv.org/abs/2405.12866) algorithms on GPUs to accelerate [BQSKit](https://github.com/bqskit/bqskit). It uses [JAX](https://jax.readthedocs.io/en/latest/index.html) as an abstraction layer of the GPUs, seamlessly utilizing JIT compilation and GPU parallelism.
+`bqskit-qfactor-jax` is a Python package that implements circuit instantiation using the [QFactor](https://ieeexplore.ieee.org/abstract/document/10313638) and [QFactor-Sample](https://arxiv.org/abs/2405.12866) algorithms on GPUs to accelerate [BQSKit](https://github.com/bqskit/bqskit). It uses [JAX](https://jax.readthedocs.io/en/latest/index.html) as an abstraction layer of the GPUs, seamlessly utilizing JIT compilation and GPU parallelism. You may refer the [GPU cluster guide](https://bqskit.readthedocs.io/en/latest/guides/usegpus.html) for detailed information on how to utilize this packge on a node with several GPUs or on a GPU cluster.
 
 ## Installation
 `bqskit-qfactor-jax` is available for Python 3.9+ on Linux. It can be installed using pip