docs: make GtkWidget:margin-start and margin-end clearer

margin-start and margin-end have been added for RTL support, see:
https://bugzilla.gnome.org/show_bug.cgi?id=710238

So those properties are used only for the horizontal direction: left or
right, not top or bottom.

https://bugzilla.gnome.org/show_bug.cgi?id=732681

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 3567b6be53925370b63379205e8c51d0f6606ef5..9bd89aa5bb10b5cd9b3e8893f3ba7135ad8d3b14 100644 (file)
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -1541,7 +1541,8 @@ G_GNUC_END_IGNORE_DEPRECATIONS
   /**
    * GtkWidget:margin-start:
    *
-   * Margin on start of widget.
+   * Margin on start of widget, horizontally. This property supports
+   * left-to-right and right-to-left text directions.
    *
    * This property adds margin outside of the widget's normal size
    * request, the margin will be added in addition to the size from
@@ -1562,7 +1563,8 @@ G_GNUC_END_IGNORE_DEPRECATIONS
   /**
    * GtkWidget:margin-end:
    *
-   * Margin on end of widget.
+   * Margin on end of widget, horizontally. This property supports
+   * left-to-right and right-to-left text directions.
    *
    * This property adds margin outside of the widget's normal size
    * request, the margin will be added in addition to the size from