Description of problem:

The proxy configuration link is not mentioned in the Prerequisites section of Agent based installation documentation[1] like it is mentioned in other installation documentation [2].

[1] https://docs.openshift.com/container-platform/4.12/installing/installing_with_agent_based_installer/installing-with-agent-based-installer.html#prerequisites_installing-with-agent-based-installer

[2] https://docs.openshift.com/container-platform/4.12/installing/installing_bare_metal/installing-bare-metal.html#prerequisites