docs(rest-api): remove '{: .opa-tip}'
docs(rest-api): remove '{: .opa-tip}'

This didn't look like it was processed in any way, and showed up as-is
on the website.

Signed-off-by: Stephan Renatus <3d1a7d0a294b6d8e799ad6e122143905f17f9530@chef.io>

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