Create checkDuplicateCommands.ts

[EndlessM0DZ]

This will warn users of duplicate command names and give the respective locations of the files. I tested this code in a simple test environment in JS, so it may need more testing and tweaks.

[vercel[bot]]

@EndlessM0DZ is attempting to deploy a commit to the Under Ctrl Team on Vercel.

A member of the Team first needs to authorize it.