auto-detect and install puppeteer dependency for default prerendering

[thescientist13]

Type of Change

• New Feature Request
• Documentation / Website
• Improvement / Suggestion
• Bug
• Other (please clarify below)

Summary

Piggy-backing off of #855, the desire is to avoid having the puppeteer dependency need to install by default given how large of a dependency it is. This is especially noticeable when running the basic npx example from the home page or if all you want to build is a more traditional HTML based site without relying on the need for a browser to prerender JS / Web Components.

Instead, it would be great to detect if prerender is set in greenwood.config.js and if so, install it on demand.

This effort also aligns with our our desire to provide a purely JavaScript solution that doesn't need a browser, per #548.

Details

I have started this work in #860 and had made some good progress, but got stuck on getting to work as expected, so this may need to be a two-parter, depending on timeliness of getting the ideal workflow implemented.

At minimum, move puppeteer to be an optionalDependency, then

1. auto install the dependency in real time when greenwood build is run
2. Or, fallback to at least communicating to the user the need to install the dependency manually, with additional documentation around the prerender setting in the documentation