[gtksourceview] docs: porting guide: gtk_source_init() needs to be called

[Sébastien Wilmet <swilmet src gnome org>]

commit a42c40dc1ba9c1d21806d7bac6c1bae949d0f05c
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sat Oct 28 14:12:01 2017 +0200

    docs: porting guide: gtk_source_init() needs to be called

 docs/reference/porting-guide-3-to-4.xml |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)
---
diff --git a/docs/reference/porting-guide-3-to-4.xml b/docs/reference/porting-guide-3-to-4.xml
index 91ca9c8..a312caf 100644
--- a/docs/reference/porting-guide-3-to-4.xml
+++ b/docs/reference/porting-guide-3-to-4.xml
@@ -168,5 +168,20 @@
         </para>
       </listitem>
     </itemizedlist>
+
+    <para>
+      Other changes in 3.99.7:
+    </para>
+    <itemizedlist>
+      <listitem>
+        <para>
+          For i18n initialization, the
+          <link linkend="gtk-source-init">gtk_source_init()</link> function
+          now needs to be called. There is also the
+          <link linkend="gtk-source-finalize">gtk_source_finalize()</link>
+          function which is convenient when using memory debugging tools.
+        </para>
+      </listitem>
+    </itemizedlist>
   </refsect1>
 </chapter>