Add PreferredCulture to IGuild

This property was defined in RestGuild and SocketGuild, so it only makes sense to make it part of IGuild as well.

src/Discord.Net.Core/Entities/Guilds/IGuild.cs

@@ -1,6 +1,7 @@
 using Discord.Audio;
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Threading.Tasks;
 
 namespace Discord
@@ -259,6 +260,14 @@ namespace Discord
         /// </returns>
         string PreferredLocale { get; }
 
+        /// <summary>
+        ///     Gets the preferred culture of this guild.
+        /// </summary>
+        /// <returns>
+        ///     The preferred culture information of this guild.
+        /// </returns>
+        CultureInfo PreferredCulture { get; }
+
         /// <summary>
         ///     Modifies this guild.
         /// </summary>

src/Discord.Net.Rest/Entities/Guilds/RestGuild.cs

@@ -68,12 +68,7 @@ namespace Discord.Rest
         /// <inheritdoc />
         public string PreferredLocale { get; private set; }
 
-        /// <summary>
-        ///     Gets the preferred culture of this guild.
-        /// </summary>
-        /// <returns>
-        ///     The preferred culture information of this guild.
-        /// </returns>
+        /// <inheritdoc />
         public CultureInfo PreferredCulture { get; private set; }
 
         /// <inheritdoc />

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -109,12 +109,7 @@ namespace Discord.WebSocket
         /// <inheritdoc />
         public string PreferredLocale { get; private set; }
 
-        /// <summary>
-        ///     Gets the preferred culture of this guild.
-        /// </summary>
-        /// <returns>
-        ///     The preferred culture information of this guild.
-        /// </returns>
+        /// <inheritdoc />
         public CultureInfo PreferredCulture { get; private set; }
 
         /// <inheritdoc />