`progress.md` is outdated

[MaxDesiatov]

We should keep this doc up-to-date with latest additions to SwiftUI and Tokamak

[carson-katri]

This seems like a good thing to automate.

Not sure how plausible this is, but maybe: Use SourceKit to get a list of View conforming types from the swiftinterface, and compare it to Tokamak. If it's miss any properties mark it as under construction with a list of the missing values. Could check for modifiers too.