Command categorisation

I really prefer extensions to have a category, and so do the Microsoft devs:

https://code.visualstudio.com/api/references/contribution-points#contributes.commands

[mitchdenny]

Hey @sndst00m what category would you suggest?

There isn't a VS Code one for utilities like "Transform to Uppercase", so Encode/Decode would be great, or ECDC as a second option.

Command IDs should ideally be the name portion of the extension ID rather than extension, but this requires people to update their custom keyboard shortcuts 🤔