Add information for DiscordSocketConfig

+ Add remarks/example to the class
+ Add remarks to AlwaysDownloadUsers

src/Discord.Net.WebSocket/DiscordSocketConfig.cs

@@ -7,6 +7,22 @@ namespace Discord.WebSocket
     /// <summary>
     ///     Represents a configuration class for <see cref="DiscordSocketClient"/>.
     /// </summary>
+    /// <remarks>
+    ///     This configuration, based on <see cref="DiscordRestConfig"/>, helps determine several key configurations the
+    ///     socket client depend on. For instance, shards and connection timeout.
+    /// </remarks>
+    /// <example>
+    ///     The following config enables the message cache and configures the client to always download user upon guild
+    ///     availability.
+    ///     <code language="cs">
+    ///     var config = new DiscordSocketConfig
+    ///     {
+    ///         AlwaysDownloadUsers = true,
+    ///         MessageCacheSize = 100
+    ///     };
+    ///     var client = new DiscordSocketClient(config);
+    ///     </code>
+    /// </example>
     public class DiscordSocketConfig : DiscordRestConfig
     {
         /// <summary>
@@ -57,6 +73,30 @@ namespace Discord.WebSocket
         /// <summary>
         ///     Gets or sets whether or not all users should be downloaded as guilds come available.
         /// </summary>
+        /// <remarks>
+        ///     <para>
+        ///         By default, Discord gateway will only send offline members if a guild has less than a certain number
+        ///         of members (determined by <see cref="LargeThreshold"/> in this library). This behaviour is why
+        ///         sometimes a user may be missing from the WebSocket cache for collections such as 
+        ///         <see cref="Discord.WebSocket.SocketGuild.Users"/>.
+        ///     </para>
+        ///     <para>
+        ///         This property ensures that whenever a guild becomes available (determined by
+        ///         <see cref="Discord.WebSocket.BaseSocketClient.GuildAvailable"/>), incomplete user chunks will be
+        ///         downloaded to the WebSocket cache.
+        ///     </para>
+        ///     <para>
+        ///         For more information, please see 
+        ///         <see href="https://discordapp.com/developers/docs/topics/gateway#request-guild-members">Request Guild Members</see>
+        ///         on the official Discord API documentation.
+        ///     </para>
+        ///     <note>
+        ///         Please note that it can be difficult to fill the cache completely on large guilds depending on the
+        ///         traffic. If you are using the command system, the default user TypeReader may fail to find the user
+        ///         due to this issue. This may be resolved at v3 of the library. Until then, you may want to consider
+        ///         overriding the TypeReader and use <see cref="DiscordRestClient.GetGuildUserAsync"/> as a backup.
+        ///     </note>
+        /// </remarks>
         public bool AlwaysDownloadUsers { get; set; } = false;
         /// <summary>
         ///     Gets or sets the timeout for event handlers, in milliseconds, after which a warning will be logged. Null