Simplify OARS; remove elementary reference

.editorconfig

@@ -1,7 +1,6 @@
 # EditorConfig <http://EditorConfig.org>
 root = true
 
-# elementary defaults
 [*]
 charset = utf-8
 end_of_line = lf

data/com.github.jeremypw.gnonograms.appdata.xml.in

@@ -12,37 +12,8 @@
       solve computer generated puzzles or design their own.
     </p>
   </description>
-  <content_rating type="oars-1.1">
-    <content_attribute id="violence-cartoon">none</content_attribute>
-    <content_attribute id="violence-fantasy">none</content_attribute>
-    <content_attribute id="violence-realistic">none</content_attribute>
-    <content_attribute id="violence-bloodshed">none</content_attribute>
-    <content_attribute id="violence-sexual">none</content_attribute>
-    <content_attribute id="violence-desecration">none</content_attribute>
-    <content_attribute id="violence-slavery">none</content_attribute>
-    <content_attribute id="violence-worship">none</content_attribute>
-    <content_attribute id="drugs-alcohol">none</content_attribute>
-    <content_attribute id="drugs-tobacco">none</content_attribute>
-    <content_attribute id="sex-nudity">none</content_attribute>
-    <content_attribute id="sex-themes">none</content_attribute>
-    <content_attribute id="sex-homosexuality">none</content_attribute>
-    <content_attribute id="sex-prostitution">none</content_attribute>
-    <content_attribute id="sex-adultery">none</content_attribute>
-    <content_attribute id="sex-appearance">none</content_attribute>
-    <content_attribute id="drugs-narcotics">none</content_attribute>
-    <content_attribute id="language-profanity">none</content_attribute>
-    <content_attribute id="language-humor">none</content_attribute>
-    <content_attribute id="language-discrimination">none</content_attribute>
-    <content_attribute id="money-purchasing">none</content_attribute>
-    <content_attribute id="money-gambling">none</content_attribute>
-    <content_attribute id="social-chat">none</content_attribute>
-    <content_attribute id="social-audio">none</content_attribute>
-    <content_attribute id="social-location">none</content_attribute>
-    <content_attribute id="social-contacts">none</content_attribute>
-    <content_attribute id="social-purchasing">none</content_attribute>
-    <content_attribute id="social-gambling">none</content_attribute>
-    <content_attribute id="social-info">none</content_attribute>
-  </content_rating>
+  <content_rating type="oars-1.1"/> 
+<!--All content attributes are "none"-->
   <categories>
     <category>Game</category>
     <category>LogicGame</category>