[gtk/ebassi/gidocgen] overlaylayout: Add docs for GtkOverlayLayoutChild

[Matthias Clasen <matthiasc src gnome org>]

commit 75e95b42c340564031bb84dfc1e6826dafd8a461
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Mar 1 01:45:50 2021 -0500

    overlaylayout: Add docs for GtkOverlayLayoutChild

 gtk/gtkoverlaylayout.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gtk/gtkoverlaylayout.c b/gtk/gtkoverlaylayout.c
index 27a95c3764..bc457719d6 100644
--- a/gtk/gtkoverlaylayout.c
+++ b/gtk/gtkoverlaylayout.c
@@ -43,6 +43,12 @@
  * properties get documented.
  */
 
+/**
+ * GtkOverlayLayoutChild:
+ *
+ * `GtkLayoutChild` subclass for children in a `GtkOverlayLayout`.
+ */
+
 struct _GtkOverlayLayout
 {
   GtkLayoutManager parent_instance;