[librsvg] RsvgDimensionData/RsvgPositionData - Add descriptions

[Federico Mena Quintero <federico src gnome org>]

commit 52d9b4302616cde8966083f3a6b93d1768ddc145
Author: Federico Mena Quintero <federico gnome org>
Date:   Thu Jan 24 18:45:30 2019 -0600

    RsvgDimensionData/RsvgPositionData - Add descriptions
    
    Why are these not showing up in the rendered docs!?

 librsvg/rsvg.h | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/librsvg/rsvg.h b/librsvg/rsvg.h
index 4a590da4..c5aed1cb 100644
--- a/librsvg/rsvg.h
+++ b/librsvg/rsvg.h
@@ -103,8 +103,12 @@ struct _RsvgHandle {
  * RsvgDimensionData:
  * @width: SVG's width, in pixels
  * @height: SVG's height, in pixels
- * @em: em
- * @ex: ex
+ * @em: SVG's original width, unmodified by #RsvgSizeFunc
+ * @ex: SVG's original height, unmodified by #RsvgSizeFunc
+ *
+ * Dimensions of an SVG image from rsvg_handle_get_dimensions(), or an
+ * individual element from rsvg_handle_get_dimensions_sub().  Please see
+ * the deprecation documentation for those functions.
  *
  * Deprecated: 2.46.  Please use rsvg_handle_get_geometry_sub().
  */
@@ -120,7 +124,8 @@ struct _RsvgHandle {
  * @x: position on the x axis
  * @y: position on the y axis
  *
- * Position of an SVG fragment.
+ * Position of an SVG fragment from rsvg_handle_get_position_sub().  Please
+ * the deprecation documentation for that function.
  *
  * Deprecated: 2.46.  Please use rsvg_handle_get_geometry_sub().
  */