Allow full invite URLs to be passed to AcceptInvite

src/Discord.Net/API/Endpoints.cs

@@ -5,6 +5,7 @@
 		public static readonly string BaseUrl = "discordapp.com";
 		public static readonly string BaseShortUrl = "discord.gg";
 		public static readonly string BaseHttps = $"https://{BaseUrl}";
+		public static readonly string BaseShortHttps = $"https://{BaseShortUrl}";
 
 		// /api
 		public static readonly string BaseApi = $"{BaseHttps}/api";
@@ -52,6 +53,6 @@
 		public static readonly string WebSocket_Hub = $"{BaseWss}/hub";
 
 		//Website
-		public static string InviteUrl(string code) => $"{BaseShortUrl}/{code}";
+		public static string InviteUrl(string code) => $"{BaseShortHttps}/{code}";
     }
 }

src/Discord.Net/DiscordClient.cs

@@ -705,6 +705,15 @@ namespace Discord
 		public async Task AcceptInvite(string id)
 		{
 			CheckReady();
+			
+			//Remove Url Parts
+			if (id.StartsWith(Endpoints.BaseShortHttps))
+				id = id.Substring(Endpoints.BaseShortHttps.Length);
+			if (id.Length > 0 && id[0] == '/')
+				id = id.Substring(1);
+			if (id.Length > 0 && id[id.Length - 1] == '/')
+				id = id.Substring(0, id.Length - 1);
+
 			//Check if this is a human-readable link and get its ID
 			var response = await DiscordAPI.GetInvite(id);
 			await DiscordAPI.AcceptInvite(response.Code);