Getting completion for R programming

[fasterius]

Thanks for a great plugin! I want to get completion for R (and, by extension, R Markdown), but that is currently not natively supported as far as I can tell. There is a language server implementation (https://github.com/REditorSupport/languageserver), and the documentation for completor does state that other languages are supported through omnicompletion. Maybe I'm not understanding how these things are supposed to work, but I have no clue what do to. Is there something more in-depth I can read up on and understand what I need to do to get it to work?