Future "Performance" page for CE3 docs

Effect type performance is usually an exercise in missing the point, but people do kind of want to hear about it. I think it's worth talking about CE3 IO's performance relative to CE2's in two specific areas:

• Straightline performance (i.e the async "deep" and "shallow" bind benchmarks)
• Contended scheduling performance

The former is something that people often talk about because it's easy to understand, but it's also not really relevant in 99% of applications. It's still fun to look at. The contended performance though is something that we're improving dramatically in CE3 due to #1095, and it's also something that people are definitely going to be able to measure in real world applications, so I think it's worth explaining and trumpeting.

It's also worth talking about JavaScript performance a bit and the intricacies of the fact that our scheduler correctly and efficiently deals with the event queue.

Start by reviewing the CE2/CE3 performance context described here and issue #1095, focusing on the deep/shallow bind and contended scheduling benchmarks. The page is done when it explains those comparisons, their real-world relevance, and JavaScript event-queue scheduling performance.