Summary

I add support for Spacemacs in the Pen.el docker image.
Pen.el on GitHub https://github.com/semiosis/pen.el/
Prompts on GitHub http://github.com/semiosis/prompts/
Tutorial https://semiosis.github.io/posts/pen-tutorial/
Discord channel invite https://discord.gg/JwKGbAdNHR

Demo

This is me doing some code-generation in Spacemacs.

And below is having inserted the code.

And below, running in Google Chrome.