update appdata

Author: danirabbit

data/com.github.danrabbit.nimbus.appdata.xml

@@ -8,6 +8,13 @@
     <summary>See outside without going there</summary>
     <description>
         <p>See the current temperature and weather conditions for your location with this minimal color-changing applet.</p>
+        <ul>
+            <li>Click anywhere to fetch the latest weather</li>
+            <li>Stays out of your way by always sticking to the desktop</li>
+            <li>Move the window by dragging any part of it</li>
+            <li>Quit with the handy shortcut Ctrl + Q</li>
+            <li>Respects your system settings for temperature units</li>
+        </ul>
     </description>
     <provides>
         <binary>com.github.danrabbit.nimbus</binary>