Search through submodules for GetExecutableCommandAsync

src/Discord.Net.Commands/Extensions/CommandServiceExtensions.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 
 namespace Discord.Commands
@@ -22,6 +23,6 @@ namespace Discord.Commands
         public static Task<IReadOnlyCollection<CommandInfo>> GetExecutableCommandsAsync(this CommandService commandService, ICommandContext context, IServiceProvider provider)
             => GetExecutableCommandsAsync(commandService.Commands, context, provider);
         public static Task<IReadOnlyCollection<CommandInfo>> GetExecutableCommandAsync(this ModuleInfo module, ICommandContext context, IServiceProvider provider)
-            => GetExecutableCommandsAsync(module.Commands, context, provider);
+            => GetExecutableCommandsAsync(module.Commands.Concat(module.Submodules.SelectMany(sm => sm.Commands)), context, provider);
     }
 }