How to load existing bash completion files with zplug?

[teutat3s]

Is your feature request related to a problem? Please describe. I would love to be able to use bash completion with bashcompinit but could't find any information on how to do it with zplug. I would be very happy if someone could explain to me how to do it - I'd then create a documentation PR based on this issue.

Describe the solution you'd like I would like to be able to use bash completion files with zplug, e.g. like ones generate for nodejs from https://github.com/trentm/node-dashdash/blob/master/etc/dashdash.bash_completion.in

Describe alternatives you've considered https://github.com/RobSis/zsh-completion-generator

Additional context Add any other context or screenshots about the feature request here.