[recipes] Update appdata

[Matthias Clasen <matthiasc src gnome org>]

commit 9884d748ef641407778522844217aa6f5dcd62e5
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Feb 27 10:24:52 2017 -0500

    Update appdata

 data/appdata/org.gnome.Recipes.appdata.xml.in |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)
---
diff --git a/data/appdata/org.gnome.Recipes.appdata.xml.in b/data/appdata/org.gnome.Recipes.appdata.xml.in
index ef9963b..a53c9b4 100644
--- a/data/appdata/org.gnome.Recipes.appdata.xml.in
+++ b/data/appdata/org.gnome.Recipes.appdata.xml.in
@@ -47,6 +47,20 @@
     </screenshot>
   </screenshots>
   <releases>
+    <release version="0.18.0" date="2017-02-27">
+      <description>
+        <p>
+          A minor update, focusing on polish and performance.
+        </p>
+        <ul>
+          <li>Improve the UI for search by spiciness</li>
+          <li>Speed up listing of recipes</li>
+          <li>Add a “What's New” dialog</li>
+          <li>New contributed recipes: Hazelnut milk, Hazelnut butter</li>
+          <li>Translation updates: German, Polish, Serbian, Spanish</li>
+        </ul>
+      </description>
+    </release>
     <release version="0.16.0" date="2017-02-25">
       <description>
         <p>