Fix inaccuracy in the Keyword Arguments Order

README.adoc

@@ -3115,7 +3115,7 @@ some_method('w', 'x', 'y', 'z') # => 'y, z, w, x'
 
 === Keyword Arguments Order
 
-Put required keyword arguments before optional keyword arguments. Otherwise, it's much harder to spot optional arguments there, if they're hidden somewhere in the middle.
+Put required keyword arguments before optional keyword arguments. Otherwise, it's much harder to spot optional keyword arguments there, if they're hidden somewhere in the middle.
 
 [source,ruby]
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