Fix typo

README.md

@@ -50,7 +50,7 @@ let correlationVector = try CorrelationVector.extend("vtul4NUsfs9Cl7mOf.1") // "
 
 ## Spin
 
-**NOTE-:** Spin operator operator can only be used on v2 correlation vectors
+**NOTE-:** Spin operator can only be used on v2 correlation vectors
 
 ```swift
 let correlationVector = CorrelationVectorV2()