Sorry for causing confusion. If you're running Vim 8, you can look up the documentation on job control by running :help channel. If you're running Neovim, the equivalent page in the documentation can be located using :help job-control.
Both Vim 8 and Neovim have similar async capabilities, but sadly their APIs differ 
The good news is that minpac works in both Vim 8 and Neovim (thanks in part to the async.vim library, which normalizes the job control APIs).
