[gtk/ebassi/for-master] docs: Add a section on a11y patterns

[Emmanuele Bassi <ebassi src gnome org>]

commit f52c86ae21507fade4080e68708451d0efd546ab
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon Oct 19 18:39:40 2020 +0100

    docs: Add a section on a11y patterns

 docs/reference/gtk/section-accessibility.md | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/docs/reference/gtk/section-accessibility.md b/docs/reference/gtk/section-accessibility.md
index 9d352f640f..5576066e2f 100644
--- a/docs/reference/gtk/section-accessibility.md
+++ b/docs/reference/gtk/section-accessibility.md
@@ -284,3 +284,7 @@ accessible label as "Download Final report.pdf".
 The power of hiding and enhancing can be a double-edged sword, as it can
 lead to inadvertently overriding the accessible semantics of existing
 widgets.
+
+## Design patterns and custom widgets
+
+...