[Settings][QuickAccent]Change 'character set' to plural form (#36565)

src/settings-ui/Settings.UI/Strings/en-us/Resources.resw

@@ -3580,10 +3580,10 @@ Activate by holding the key for the character you want to add an accent to, then
     <value>Characters</value>
   </data>
   <data name="QuickAccent_SelectedLanguage.Header" xml:space="preserve">
-    <value>Choose a character set</value>
+    <value>Choose character sets</value>
   </data>
   <data name="QuickAccent_SelectedLanguage.Description" xml:space="preserve">
-    <value>Show only accented characters common to the selected set</value>
+    <value>Show only accented characters common to the selected sets</value>
   </data>
   <data name="QuickAccent_SelectedLanguage_All.Content" xml:space="preserve">
     <value>All available</value>