Draft: New Support Team Member Start Here: add hybrid model step in final stage

This MR builds on work done in an OKR from FY22, which created the mermaid diagram for the Support hybrid onboarding model, and is part of improvements being put forward together in support-team-meta#4048 (closed).

This MR adds a step in the Final Stage of the New Support Team Member Start Here issue template for the engineer and manager to review the hybrid model and determine the first Area of Focus.

Previously, the Issue Template referenced the Area of Focus, but did not direct you to the hybrid model. This MR also makes this a collaborative step between engineer-manager, which is how it works in practice.