[fractal] release: write release notes

[Julian Sparber <jsparber src gnome org>]

commit a8dec5f8bd64fa3ed9beb87e9e1580699109b219
Author: Alexandre Franke <alexandre franke gmail com>
Date:   Mon Dec 17 23:21:38 2018 +0100

    release: write release notes

 .../res/org.gnome.Fractal.appdata.xml.in.in        | 25 +++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)
---
diff --git a/fractal-gtk/res/org.gnome.Fractal.appdata.xml.in.in 
b/fractal-gtk/res/org.gnome.Fractal.appdata.xml.in.in
index 983309a..661cf5f 100644
--- a/fractal-gtk/res/org.gnome.Fractal.appdata.xml.in.in
+++ b/fractal-gtk/res/org.gnome.Fractal.appdata.xml.in.in
@@ -18,7 +18,30 @@
     </screenshot>
   </screenshots>
   <releases>
-    <release version="3.99.0" date="2018-12-14"/>
+    <release version="4.0.0" type="stable" date="2018-12-18" urgency="high">
+      <description>
+        <p>This new major release is the result of 3 months of hard work by 25 contributors pushing over 340 
commits.</p>
+        <p>New features:</p>
+        <ul>
+          <li>Enhanced history view with adaptive layout, day divider</li>
+          <li>Larger display of emoji-only messages</li>
+          <li>Some performance improvements</li>
+         <li>Opening a room jumps to first unread message</li>
+        </ul>
+        <p>Bugfixes:</p>
+        <ul>
+          <li>More reliable notifications</li>
+          <li>Fixed display bug for avatars</li>
+        </ul>
+        <p>Under the hood:</p>
+        <ul>
+          <li>Large code refactor</li>
+          <li>Logging infrastructure</li>
+          <li>Continuous integration</li>
+          <li>More informative build output</li>
+        </ul>
+      </description>
+    </release>
   </releases>
   <update_contact>danigm wadobo com</update_contact>