Add routing table lifecycle diagram to documentation

[arschles]

@tpiperatgod created a great lifecycle diagram for the routing table in https://github.com/kedacore/http-add-on/pull/326#issuecomment-972946943. It would be very useful to add this diagram to documentation.

Use-Case

I think this diagram would be very helpful especially for HTTP Addon developers looking to understand the system better. I bet it would also help operators trying to troubleshoot.

Specification

The diagram should be added either to an existing document or added to a new one.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 7 days if no further activity occurs. Thank you for your contributions.

[JorTurFer]

This doesn't apply as we don't use the table any more