[gtk] Fix gdk docs build

[Matthias Clasen <matthiasc src gnome org>]

commit be25905a8d2735b80aebcee69fdace3e8a4092de
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Feb 22 10:43:37 2020 -0500

    Fix gdk docs build

 docs/reference/gdk/gdk4-sections.txt | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)
---
diff --git a/docs/reference/gdk/gdk4-sections.txt b/docs/reference/gdk/gdk4-sections.txt
index bd420817bc..b6f297238b 100644
--- a/docs/reference/gdk/gdk4-sections.txt
+++ b/docs/reference/gdk/gdk4-sections.txt
@@ -651,6 +651,17 @@ gdk_paintable_get_intrinsic_height
 gdk_paintable_get_intrinsic_aspect_ratio
 gdk_paintable_compute_concrete_size
 
+<SUBSECTION>
+gdk_paintable_invalidate_contents
+gdk_paintable_invalidate_size
+gdk_paintable_new_empty
+
+<SUBSECTION Private>
+GDK_TYPE_PAINTABLE
+gdk_paintable_get_type
+</SECTION>
+
+
 <SECTION>
 <FILE>gdkpopuplayout</FILE>
 <TITLE>GdkPopupLayout</TITLE>
@@ -675,16 +686,6 @@ gdk_popup_layout_set_offset
 gdk_popup_layout_get_offset
 </SECTION>
 
-<SUBSECTION>
-gdk_paintable_invalidate_contents
-gdk_paintable_invalidate_size
-gdk_paintable_new_empty
-
-<SUBSECTION Private>
-GDK_TYPE_PAINTABLE
-gdk_paintable_get_type
-</SECTION>
-
 <SECTION>
 <TITLE>Textures</TITLE>
 <FILE>textures</FILE>