Adjusted metainfo to pass flathub linter

docs/appdata/flameshot.metainfo.xml

@@ -1,10 +1,12 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Copyright 2018 Vitaly Zaitsev <vitaly@easycoding.org> -->
-<component type="desktop">
+<component type="desktop-application">
   <id>org.flameshot.flameshot</id>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>GPL-3.0-or-later</project_license>
   <name>Flameshot</name>
+  <releases> 
+	  <release version="0.8" date="2020-09-23"/>
+  </releases>
   <summary>Powerful and simple to use screenshot software</summary>
   <description>
     <p>
@@ -12,6 +14,8 @@
       editor with advanced features.
     </p>
   </description>
+  <content_rating type="oars-1.1" />
+  <translation type="qt">flameshot</translation>
   <screenshots>
     <screenshot type="default">
       <image>https://raw.githubusercontent.com/flameshot-org/flameshot/master/data/img/preview/usageStatic.png</image>
@@ -23,4 +27,5 @@
   <url type="homepage">https://github.com/flameshot-org/flameshot</url>
   <update_contact>https://github.com/flameshot-org/flameshot/issues/new</update_contact>
   <launchable type="desktop-id">flameshot.desktop</launchable>
+
 </component>