Add "ZoneSettings" extensions

Extensions/Cloudflare.Zones/Models/Settings/IPV6.cs

@@ -0,0 +1,23 @@
+namespace AMWD.Net.Api.Cloudflare.Zones
+{
+	/// <summary>
+	/// Enable IPv6 on all subdomains that are Cloudflare enabled.
+	/// (<see href="https://support.cloudflare.com/hc/en-us/articles/200168586"/>).
+	/// </summary>
+	public class IPV6 : ZoneSettingBase
+	{
+		/// <summary>
+		/// Initializes a new instance of the <see cref="IPV6"/> class.
+		/// </summary>
+		public IPV6()
+		{
+			Id = ZoneSettingId.IPV6;
+		}
+
+		/// <summary>
+		/// Current value of the zone setting.
+		/// </summary>
+		[JsonProperty("value")]
+		public OnOffState Value { get; set; }
+	}
+}