Require user to be in chat to queue (#5)

Co-authored-by: Myx <info@azaaxin.com>

Bot/Handler/MusicPlayer/PlayCommand/PlayHandler.cs

@@ -45,10 +45,17 @@ public class PlayHandler : IRequestHandler<PlayCommand>
 
         async void PlayMusic()
         {
-            await _audioService.StartAsync(cancellationToken);
             var context = command.Message;
             _context = context;
             
+            if ((context.User as SocketGuildUser)?.VoiceChannel == null)
+            {
+                await context.SendMessageAsync("You must be in a voice channel to use this command.", _client);
+                return;
+            }
+            
+            await _audioService.StartAsync(cancellationToken);
+
             var searchQuery = context.GetOptionValueByName(Option.Input);
 
             if (string.IsNullOrWhiteSpace(searchQuery))