feat: add annotation to add command description

src/main/kotlin/cn/rtast/fancybot/commands/niuzi/NiuziSignCommand.kt

@@ -7,12 +7,14 @@
 
 package cn.rtast.fancybot.commands.niuzi
 
+import cn.rtast.fancybot.annotations.CommandDescription
 import cn.rtast.fancybot.niuziManager
 import cn.rtast.rob.entity.GroupMessage
 import cn.rtast.rob.util.BaseCommand
 import cn.rtast.rob.util.ob.MessageChain
 import cn.rtast.rob.util.ob.OneBotListener
 
+@CommandDescription("牛子签到~")
 class NiuziSignCommand : BaseCommand() {
     override val commandNames = listOf("牛子签到", "签到")