docs: Add policy-style discussion to faq
docs: Add policy-style discussion to faq

Signed-off-by: Tim Hinrichs <5ee0edb9e2229c0838f1959779f1949031de0123@styra.com>

open-policy-agent/opa,tsandall/opa,open-policy-agent/opa,tsandall/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa,open-policy-agent/opa,open-policy-agent/opa,tsandall/opa,tsandall/opa