Add lighthouse checks to build for perf testing

[mattstratton]

Investigate adding this action to the build/PR process: https://github.com/GoogleChrome/lighthouse-ci

[mattstratton]

I think this will possibly work if we use this action as well to get the hugo site(s) built?

https://github.com/peaceiris/actions-hugo

GitHub

peaceiris/actions-hugo

GitHub Actions for Hugo ⚡️ Setup Hugo quickly and build your site fast. Hugo extended, Hugo Modules, Linux (Ubuntu), macOS, and Windows are supported. - peaceiris/actions-hugo

[mattstratton]

In #319 I got the initial setup done, but it's not complete. I want to merge that PR, but leave this issue open since there are a few more things to do:

Currently only tests the default configuration. I need to do some more research on GH actions to figure out how to do a better matrix test (similar to what we do with circle; I don't think we have to test every color permutation, but we should check the following:

• blue-grid
• blue-row-jumbo-false
• blue-row-jumbo-true

[mattstratton]

I got this mostly working. The overall status check will only report on one, so you have to dig into each one to see all the reports for each configuration. But that's probably fine.