npm install on docs takes a long time

[shanejonas]

Describe the bug
When generating a new project with docs, the npm install takes a while because it requires puppeteer which downloads chromium.

This is used for markdown files and mermaidjs support.

If you do not plan on using these features you can speed up the npm install by setting an environment variable:

Workaround
export PUPPETEER_SKIP_CHROMIUM_DOWNLOAD=1

npm install .