How to embed only one cell?

Hello,
I can’t find in the documentation how to do this.
I want to embed only one cell of the notebook to keep the visible code clean. I noticed rambda docs - https://ramdajs.com/docs/ have it set up that way with importing the package in a different cell while still having access to the variables in the visible code.
How can I achieve the same effect?

Hi there,

Check out the preamble field in the Embeds documentation here: https://runkit.com/docs/embed

- Randy