add command validator

[xcfio]

This is a command validator that check command name, description, and option according to https://discord.com/developers/docs/interactions/application-commands#application-command-object

[vercel[bot]]

@xcfio is attempting to deploy a commit to the Under Ctrl Team on Vercel.

A member of the Team first needs to authorize it.

[twlite]

Hi @xcfio, thank you for the pr. While command name validation makes sense, it's best to let discord validate this. If discord changes this from their side, we'd need to update the code again.