[racket-dev] package-system update

As one of those people on the periphery, wanted to share some
feedback. I hope it's not so high-level that it's vague and annoying.

1. Racket has a wonderful story about simple installation.

On Windows, Mac, Linux, you download one file, run it, and it's all
set up and good to go in < 1 minute. (Plus there's this amazing IDE,
DrRacket.)

In my limited experience the story is not as wonderful with some
more-popular languages. Which is fortunate; ideally the barrier to
trying Racket should be lower.

For many users, a monolithic(ish) simple install will remain a wonderful thing.

As best I understand, the proposal isn't to get rid of that, instead
it's to supplement it with more options. If so, (a) great! And (b),
this may still be tricky because we wouldn't want that _message_ to
get obscured when announcing the new, more sophisticated thing. (In
commercial software marketing I've seen companies want to emphasize
new features, to the detriment of telling the basic story which is
still fresh and compelling for new users (just not to existing users,
or to the sales/marketing guys who are getting bored with it).
Although that concern may be unwarranted, here, I wanted to point out
the potential gotcha.)

2. The new package system has already proven to be an easier
experience for third party package authors like me. That is great --
thank you!

3. As a very infrequent contributor to Racket, I'm just sort of
waiting for the dust to settle with respect to Git repo (repos??) and
build process, at which point I'll be eager to contribute again.

3(a) Speaking of which, I think there is some backlog of pull requests
on GitHub. Would it be simpler to to accept any more of these before
the source layout universe changes, or too much to deal with so punt
until later?  (I don't know either way, just wanted to point it out.)