Necessary changes for Flatpak release

data/de.zwarf.picplanner.appdata.xml.in

@@ -6,8 +6,10 @@
 	<name>PicPlanner</name>
 	<summary>Photograph location planning application</summary>
 	<description>
-		This application is designed to calculate the position of the sun,
-		moon and milky way to plan the perfect time to take a photograph.
+		<p>
+			This application is designed to calculate the position of the sun,
+			moon and milky way to plan the perfect time to take a photograph.
+		</p>
 	</description>
 	<screenshots>
 		<screenshot type="default">