add link to custom instances guide

Author: malcolmbarrett

chapters/05-computing.qmd

@@ -6,6 +6,8 @@ Stanford's [Nero Google Cloud Platform (GCP)](https://nero-docs.stanford.edu/gcp
 
 If you have questions about which environment you should use for your data analyses, please ask so we can be certain to follow all data security and privacy requirements.
 
+To set up and manage a compute instance on Nero GCP, follow the [lab guide for custom instances](https://github.com/StanfordHPDS/nero_setup) (note that this is a private repository). 
+
 ## Sherlock {#sec-sherlock}
 
 Stanford has a High Performance Computing cluster called [Sherlock](https://www.sherlock.stanford.edu/docs/). See this information on [getting started](https://www.sherlock.stanford.edu/docs/getting-started/), [connecting](https://www.sherlock.stanford.edu/docs/getting-started/connecting/), and [submitting jobs](https://www.sherlock.stanford.edu/docs/getting-started/submitting/).