[gtksourceview] docs: document which GTK+ version is used

[Sébastien Wilmet <swilmet src gnome org>]

commit e5d36e29bd2455f917908a51318d693ad6df048d
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Thu Nov 3 18:43:42 2016 +0100

    docs: document which GTK+ version is used

 docs/reference/intro.xml.in |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/intro.xml.in b/docs/reference/intro.xml.in
index e515e7c..d95c995 100644
--- a/docs/reference/intro.xml.in
+++ b/docs/reference/intro.xml.in
@@ -21,6 +21,10 @@
     See the <ulink url="https://wiki.gnome.org/Projects/GtkSourceView";>GtkSourceView website</ulink>.
   </para>
 
+  <para>
+    GtkSourceView @GSV_MAJOR_API_VERSION@ depends on GTK+ 3.
+  </para>
+
   <refsect1>
     <title>pkg-config name</title>
     <para>