Add some of your other audits

[jkup]

I would love to have a centralized repo for perf audits. I know @paulirish and @samccone have done some that I have bookmarked. Mainly:

• RAIL & user-centric performance
• Tumblr perf

Would it be worthwhile to add those to this repo and link to them all from the readme?

[paulirish]

tumblr was added to the readme at some point

also hello! randomly cleaning up stuff from years ago lol