Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
This card is used to Ritual Summon "Crab Turtle". You must also offer monsters whose total Level Stars equal 8 or more as a Tribute from the field or your hand.
--亀の誓い
--Turtle Oath
local s,id=GetID()
function s.initial_effect(c)
	Ritual.AddProcGreaterCode(c,8,nil,91782219)
end