What would be the best way for a plugin to use null-ls?

[joshpetit]

I'm planning on adding some functionality to the xbase project (proposal) and want to add code actions. I'm wondering if the best way to go about using null-ls in a plugin that other people will be using would be to handle registering the code actions manually using the "null-ls.register" function or doing something similar to builtins where you can add xbase as a source in the same way.

If it's the latter (where users can configure adding xbase as a source) what would be the best way to create the source? In my personal usage I always just use .register, but would the sources I add there work the same if added to the sources in the setup function? Advice would be appreciated!

[jose-elias-alvarez]

See cspell.nvim for an example.