Yardoc: Fix default value style
@@ -969,8 +969,7 @@ Draw_clone(VALUE self)
* @param image [Magick::Image] the image
* @return [Magick::Draw] self
*
- * @overload composite(x, y, width, height, image, operator)
- * - Default operator is {Magick::OverCompositeOp}.
+ * @overload composite(x, y, width, height, image, operator = Magick::OverCompositeOp)
* - The "image" argument can be either an ImageList object or an Image
* argument.
* @param x [Float] x position
