2.13 collection conversion documentation mentions deprecated import

In https://docs.scala-lang.org/overviews/collections-2.13/conversions-between-java-and-scala-collections.html we have the block indicating the converters import as `import collection.JavaConverters._` which triggers a deprecation warning.
As the documentation is 2.13 focused, it would be better to indicate `import scala.jdk.CollectionConverters._` instead.