fix to slowmode cmd

src/commands/slowmode.ts

@@ -18,7 +18,7 @@ export default class Slowmode extends Command {
 
   public async run(message: Message<GuildTextableChannel>, args: string[]) {
     try {
-      if (!args[0]) return this.error(message.channel, 'This command requires an argument.');
+      if (!args[0]) return this.client.commands.get('help').run(message, [this.name]);
 
       const [length, unit] = args[0].match(this.regex);
       if (Number.isNaN(Number(length))) return this.error(message.channel, 'Could not determine the slowmode time.');