Fix formatting in system architecture documentation

Author: weekenthralling

docs/source/contributors/system-architecture.md

@@ -4,7 +4,7 @@ Below are sections presenting details of the Enterprise Gateway internals and ot
 
 ## Enterprise Gateway Process Proxy Extensions
 
-Enterprise Gateway is follow-on project to Jupyter Kernel Gateway with additional abilities to support remote kernel sessions on behalf of multiple users within resource-managed frameworks such as [Apache Hadoop YARN](https://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/YARN.html) or [Kubernetes](https://kubernetes.io/). Enterprise Gateway introduces these capabilities by extending the existing class hierarchies for `AsyncKernelManager` and `AsyncMultiKernelManager` classes, along with an additional abstraction known as a _process proxy_.
+Enterprise Gateway is follow-on project to Jupyter Kernel Gateway with additional abilities to support remote kernel sessions on behalf of multiple users within resource-managed frameworks such as [Apache Hadoop YARN](https://hadoop.apache.org/docs/stable/hadoop-yarn/hadoop-yarn-site/YARN.html) or [Kubernetes](https://kubernetes.io/). Enterprise Gateway introduces these capabilities by extending the existing class hierarchies for `AsyncKernelManager` and `AsyncMultiKernelManager` classes, along with an additional abstraction known as a _process proxy_.
 
 ### Overview