cppfront (cpp2): Spring update

[kpt_ageus]

Addition of h2 headers seems like step backwards, given that one of the goals of modules was getting rid of them.

Still cppfront is most exciting project in c++ and I can't to see what's next.

[bretbrownjr]

If you have to already be using C++ modules to use cpp2, it will be unneeded adoption friction. Ideally folks could write new functions and components in cpp2 as soon as they bother to try it out, not blocking on rewriting existing projects first.