Fix markdown link format (#37715)

packages/flutter/lib/src/material/text_field.dart

@@ -198,7 +198,8 @@ class _TextFieldSelectionGestureDetectorBuilder extends TextSelectionGestureDete
 ///    [TextField]. The [EditableText] widget is rarely used directly unless
 ///    you are implementing an entirely different design language, such as
 ///    Cupertino.
-///  * Learn how to use a [TextEditingController] in one of our [cookbook recipe]s.(https://flutter.dev/docs/cookbook/forms/text-field-changes#2-use-a-texteditingcontroller)
+///  * Learn how to use a [TextEditingController] in one of our
+///    [cookbook recipe](https://flutter.dev/docs/cookbook/forms/text-field-changes#2-use-a-texteditingcontroller)s.
 class TextField extends StatefulWidget {
   /// Creates a Material Design text field.
   ///