Add command tab completion

[Halogly]

What feature do you want to see added?

I hope to add a command completion function so that the user experience will be better.

Are there any alternatives?

I'm a beginner, I tried to look at the source code, it stands to reason that spigot has a TabExecutor function to implement the command function and Tab completion, but the source code uses the ExecutableCommand function, I don't know how to add code completion.

Anything else?

No response