improvement: Print array contents instead of toString

Martin was adamant that we should always use toString instead of pprint which we use for Scala 2, but for Arrays it is quite useless and it seems REPL is also printing contents.

runtime/src/main/scala-3/mdoc/internal/document/Printing.scala

@@ -15,6 +15,9 @@ object Printing {
   }
 
   inline private def nullableToString[T](value: T) = {
-    if (value != null) value.toString else "null"
+    value match
+      case arr: Array[_] => arr.mkString("Array(", ", ", ")")
+      case null => "null"
+      case _ => value.toString()
   }
 }

tests/worksheets/src/test/scala/tests/worksheets/WorksheetSuite.scala

@@ -71,6 +71,27 @@ class WorksheetSuite extends BaseSuite {
        |""".stripMargin
   )
 
+  checkDecorations(
+    "arrays",
+    """
+      |val x = Array(1, 2, 3)
+      |val y = Array("a", "b")
+      |""".stripMargin,
+    """|<val x = Array(1, 2, 3)> // : Array[Int] = Array...
+       |x: Array[Int] = Array(1, 2, 3)
+       |<val y = Array("a", "b")> // : Array[String] = Ar...
+       |y: Array[String] = Array("a", "b")
+       |""".stripMargin,
+    compat = Map(
+      Compat.Scala3 ->
+        """|<val x = Array(1, 2, 3)> // : Array[Int] = Array...
+           |x: Array[Int] = Array(1, 2, 3)
+           |<val y = Array("a", "b")> // : Array[String] = Ar...
+           |y: Array[String] = Array(a, b)
+           |""".stripMargin
+    )
+  )
+
   checkDecorations(
     "infix",
     """|import scala.language.postfixOps