The link in the documentation in section 2.2.4.3 to Analyzing Cluster Capacity is broken.
It should be https://docs.openshift.com/container-platform/4.6/nodes/clusters/nodes-cluster-resource-levels.html

The Quotas and Limit Ranges link is also broken it should be
https://docs.openshift.com/container-platform/4.6/applications/quotas/quotas-setting-per-project.html

And the Setting Limit Ranges link is also broken it should be
https://docs.openshift.com/container-platform/4.6/nodes/clusters/nodes-cluster-limit-ranges.html