[gtk/matthiasc/for-master] docs: Document more accessible roles

[Matthias Clasen <matthiasc src gnome org>]

commit cbb6828657d84485af8806845f53e943f0873ddb
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Oct 20 23:19:30 2020 -0400

    docs: Document more accessible roles
    
    Document that GtkText is skipped in accessibility.

 gtk/gtktext.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gtk/gtktext.c b/gtk/gtktext.c
index 59f68d04f7..7f3d064a94 100644
--- a/gtk/gtktext.c
+++ b/gtk/gtktext.c
@@ -122,6 +122,12 @@
  * CSS nodes with name cursor-handle. They get the .top or .bottom style class
  * depending on where they are shown in relation to the selection. If there is
  * just a single handle for the text cursor, it gets the style class .insertion-cursor.
+ *
+ * # Accessibility
+ *
+ * GtkText uses the #GTK_ACCESSIBLE_ROLE_NONE role, which causes it to be skipped
+ * for accessibility. This is because GtkText is expected to be used as a delegate
+ * for a #GtkEditable implementation that will be represented to accessibility.
  */
 
 #define NAT_ENTRY_WIDTH  150