Add conditional formatting to the spreadsheet

[mgifford]

I wondered about ways to improve the Google template in the future. A Lighthouse Parade Template v2.1 could include conditional formatting. That's a really easy way to highlight which pages are the biggest problem.

I would like to be able to have the default Google Lighthouse View to align with the number (out of 100%) that Google Lighthouse gives you. Yes, it's just .95 or whatever, but would be easier to see.

Might also be good to bold that so that although it is clear that there are others the primary view that most of us are familiar with is highlighted.

Also, might be worth adding a sheet at the back which points to the GitHub repo with some context about how it is run.

Ideally the date that the scan was run would be featured somewhere too.