Update _overviews/core/collections-migration-213.md

Co-Authored-By: Dale Wijnand <344610+dwijnand@users.noreply.github.com>

Author: eed3si9n

_overviews/core/collections-migration-213.md

@@ -34,7 +34,7 @@ The module also provides [migratrion rules](https://github.com/scala/scala-colle
 
 In Scala 2.13 `scala.Seq[+A]` is an alias for `scala.collection.immutable.Seq[A]`, instead of `scala.collection.Seq[A]`. This change requires some planning depending on how your code is going to be used.
 
-If you're making an application, and simply migrating Scala 2.12 code base to 2.13, it might be ok to keep using `scala.Seq` in your code.
+If you're making an application, and simply migrating a Scala 2.12 code base to 2.13, it might be ok to keep using `scala.Seq` in your code.
 
 If you're making a library intended to be used by other programmers, then using `scala.Seq` or vararg is going to be a breaking change in the API semantics. For example, if there was a function `def orderFood(order: Seq[Order]): Seq[Food]`, previously the library user would have been able to pass in an array of `Order`, but it won't work for 2.13.