docs: Fix typo on README (#56)

README.md

@@ -147,7 +147,7 @@ Result id1 = id.parse("yeah");
 Result id2 = id.parse("f12");
 ```
 
-The method `String` returns `Result`, which is either an instance of `Success`
+The method `parse` returns `Result`, which is either an instance of `Success`
 or `Failure`. In both examples above we are successful and can retrieve the
 parse result using `Success#get()`: