Add DCI Matrix for Quad R&R

Why is this change being made?

In the PLT offsite, we discussed challenges related to the Roles and Responsibilities of the Quad. This DCI chart is meant to streamline and provide a high-level guide for roles

Google Sheet for contribution since markdown tables can be a pain https://docs.google.com/spreadsheets/d/1MBJaZobIzysv2t04LTc2hBIQEMliS_nAEt9_Kzu4do4/edit?usp=sharing

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