[Feature] User primary guild (#3156)

src/Discord.Net.Rest/Entities/Users/RestUser.cs

@@ -72,6 +72,8 @@ namespace Discord.Rest
         /// <inheritdoc />
         public ulong? AvatarDecorationSkuId { get; private set; }
 
+        /// <inheritdoc />
+        public PrimaryGuild? PrimaryGuild { get; private set; }
 
         internal RestUser(BaseDiscordClient discord, ulong id)
             : base(discord, id)
@@ -126,6 +128,18 @@ namespace Discord.Rest
                 AvatarDecorationHash = model.AvatarDecoration.Value?.Asset;
                 AvatarDecorationSkuId = model.AvatarDecoration.Value?.SkuId;
             }
+
+            if (model.PrimaryGuild.IsSpecified)
+            {
+                if (model.PrimaryGuild.Value is null)
+                    PrimaryGuild = null;
+                else
+                    PrimaryGuild = new(
+                        model.PrimaryGuild.Value.GuildId,
+                        model.PrimaryGuild.Value.IdentityEnabled,
+                        model.PrimaryGuild.Value.Tag,
+                        model.PrimaryGuild.Value.BadgeHash);
+            }
         }
 
         /// <inheritdoc />