[gtksourceview] Doc lang-reference: add a missing contained element

[Sébastien Wilmet <swilmet src gnome org>]

commit 329f4cb3342571df2267c071948168de5dc23330
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Mon Nov 25 22:24:29 2013 +0100

    Doc lang-reference: add a missing contained element

 docs/reference/lang-reference.xml |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/lang-reference.xml b/docs/reference/lang-reference.xml
index d741480..2d98ad1 100644
--- a/docs/reference/lang-reference.xml
+++ b/docs/reference/lang-reference.xml
@@ -455,6 +455,7 @@ can only put sub-pattern contexts.
 Contained elements:
 <simplelist type="inline">
 <member><code>&lt;match&gt;</code> (mandatory)</member>
+<member><code>&lt;include&gt;</code> (optional)</member>
 </simplelist>.
 </para>