[Feature] Polls (#2902)

no breakings hopefully

src/Discord.Net.Core/DiscordConfig.cs

@@ -257,6 +257,21 @@ namespace Discord
         /// </summary>
         public const int MaxEntitlementsPerBatch = 100;
 
+        /// <summary>
+        ///     Returns the maximum number of poll answer voters that can be gotten per-batch.
+        /// </summary>
+        public const int MaxPollVotersPerBatch = 100;
+
+        /// <summary>
+        ///     Returns the maximum length of a poll answer text.
+        /// </summary>
+        public const int MaxPollAnswerTextLength = 55;
+
+        /// <summary>
+        ///     Returns the maximum length of a poll question text.
+        /// </summary>
+        public const int MaxPollQuestionTextLength = 300;
+      
         /// <summary>
         ///     Returns the maximum number of bans that can be banned in a single bulk request.
         /// </summary>