fix validation issues and add screenshot.

org.eyecreate.qiflora.appdata.xml

@@ -4,10 +4,20 @@
   <name>QiFlora</name>
   <summary>Mobile friendly application to monitor Mi Flora devices.</summary>
   <metadata_license>FSFAP</metadata_license>
-  <project_license>GPL-3+</project_license>
+  <project_license>GPL-3.0-or-later</project_license>
+  <content_rating type="oars-1.1" />
+  <url type="homepage">https://git.eyecreate.org/eyecreate/qiflora</url>
   <developer_name>eyecreate</developer_name>
   <description>
     <p>Mobile friendly application to monitor Mi Flora devices.</p>
     <p>Plants using this device will have thier data logged when app is used and graphed to better monitor plant health.</p>
   </description>
+  <screenshots>
+      <screenshot type="default">
+          <image type="source">https://git.eyecreate.org/eyecreate/qiflora/raw/v1.0/packaging/main_window.png</image>
+      </screenshot>
+  </screenshots>
+  <releases>
+      <release version="1.0" date="2019-11-8" type="stable"/>
+  </releases>
 </component>

org.eyecreate.qiflora.desktop

@@ -7,4 +7,4 @@ MimeType=application/x-qiflora;
 Icon=org.eyecreate.qiflora
 Type=Application
 Terminal=false
-Categories=Qt;KDE;
+Categories=Utility;Qt;KDE;