Use a better example than array

Author: dwijnand

_overviews/core/collections-migration-213.md

@@ -43,7 +43,7 @@ a method such as `orderFood(xs: _*)` the varargs parameter `xs` must be an immut
 Therefore any method signature in Scala 2.13 which includes `scala.Seq`, varargs, or `scala.IndexedSeq` is going
 to have a breaking change in API semantics (as the immutable sequence types require more, immutability, than the
 not-immutable types).  For example, with a method like `def orderFood(order: Seq[Order]): Seq[Food]`, previously
-the method user would have been able to pass in an array of `Order`, but that won't work for 2.13.
+the method user would have been able to pass in an `ArrayBuffer` of `Order`, but that won't work for 2.13.
 
 ### Migrating varargs