Added description to IPv6 switch

app/src/main/res/values/strings.xml

@@ -116,6 +116,7 @@ however it is impossible to guarantee NetGuard will work correctly on every devi
 
     <string name="summary_tethering">Depending on the Android version, tethering may work or may not work. Tethered traffic cannot be filtered.</string>
     <string name="summary_lan">Allow applications to connect to local area network addresses, like 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16</string>
+    <string name="summary_ip6">Route IP version 6 traffic to NetGuard so it can selectively be allowed or blocked</string>
     <string name="summary_wifi_home">Apply Wi-Fi network rules for selected network only (apply mobile network rules for other Wi-Fi networks)</string>
     <string name="summary_metered">Apply mobile network rules to metered (paid, tethered) Wi-Fi networks</string>
     <string name="summary_metered_2g">Apply Wi-Fi network rules for 2G data connections</string>

app/src/main/res/xml-v14/preferences.xml

@@ -75,6 +75,7 @@
         <CheckBoxPreference
             android:defaultValue="true"
             android:key="ip6"
+            android:summary="@string/summary_ip6"
             android:title="@string/setting_ip6" />
         <MultiSelectListPreference
             android:defaultValue="@array/default_wifi_home"

app/src/main/res/xml-v21/preferences.xml

@@ -75,6 +75,7 @@
         <eu.faircode.netguard.SwitchPreference
             android:defaultValue="true"
             android:key="ip6"
+            android:summary="@string/summary_ip6"
             android:title="@string/setting_ip6" />
         <MultiSelectListPreference
             android:defaultValue="@array/default_wifi_home"