Proposal: Add the es-optimizer as an option for ShowJS

A lot of times I use the ShowJS tab to do a quick-and-dirty performance evaluation of PS code before I use it in a repo. These days, almost all of my repos are using the es-optimizer, so my quick-and-dirty flow no longer works. I'm wondering if it's too much trouble to wire up the backend optimizer to trypurescript as an option?

Start by locating the ShowJS tab and the backend optimizer integration in trypurescript. Determine how optimizer choices are currently represented and whether es-optimizer can be exposed as an option. Done means the ShowJS performance-evaluation flow can use es-optimizer.