Added Channel documentation

src/Discord.Net/Channel.cs

@@ -8,26 +8,37 @@ namespace Discord
 	{
 		private readonly DiscordClient _client;
 
+		/// <summary> Returns the unique identifier for this channel. </summary>
 		public string Id { get; }
 
 		private string _name;
+		/// <summary> Returns the name of this channel. </summary>
 		public string Name { get { return !IsPrivate ? $"#{_name}" : $"@{Recipient.Name}"; }  internal set { _name = value; } }
 
+		/// <summary> Returns false is this is a public chat and true if this is a private chat with another user (see Recipient). </summary>
 		public bool IsPrivate { get;  }
+		/// <summary> Returns the type of this channel (see ChannelTypes). </summary>
 		public string Type { get; internal set; }
-		
+
+		/// <summary> Returns the id of the server containing this channel. </summary>
 		public string ServerId { get; }
+		/// <summary> Returns the server containing this channel. </summary>
 		[JsonIgnore]
 		public Server Server => ServerId != null ? _client.GetServer(ServerId) : null;
 
+		/// For private chats, returns the Id of the target user, otherwise null.
 		[JsonIgnore]
 		public string RecipientId { get; internal set; }
+		/// For private chats, returns the target user, otherwise null.
 		public User Recipient =>  _client.GetUser(RecipientId);
 
+		/// <summary> Returns a collection of all messages the client has in cache. </summary>
+		/// <remarks> This collection does not guarantee any ordering. </remarks>
 		[JsonIgnore]
 		public IEnumerable<Message> Messages => _client.Messages.Where(x => x.ChannelId == Id);
 
-		//Not Implemented
+		//TODO: Not Implemented
+		/// <summary> Not implemented, stored for reference. </summary>
 		public object[] PermissionOverwrites { get; internal set; }
 
 		internal Channel(string id, string serverId, DiscordClient client)