docs: add ControlPlane to ADOPTERS
docs: add ControlPlane to ADOPTERS

Signed-off-by: Andrew Martin <c28cb1520562e8c964138790b96cde38c9b5fe77@gmail.com>

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