This example is part of this blog entry and shows how to use rollup to create a custom bundle with the library d3-composite-projections.
To use this example, just download the files from the gist
git clone https://gist.github.com/0e73c92391def44331d2069755edc199.git
and then:
npm install
npm run build
I took the information from this post by Richa Vyas.