[Enhancement] List and explain any and all external dependencies

[windowsrefund]

Description

In light of 4226, I'd like to see a page focused on these questions:

• What external dependencies exist?
• For each of the above:
  • How does Kyverno use it?
  • Can it be bypassed? If so, how?
  • What is the impact of it not being available?

Slack discussion

https://kubernetes.slack.com/archives/CLGR9BJU9/p1658238495198669