Tweak quip for "welcome back".

I'd like to indicate that a lot has changed, and "Modern" perl != perl4 etc

Tho I'm struggling to find a good way to phrase it.
Feedback from Aaron : remove -j and make cpanm on windows non optional

-j is a detail more for advanced users, and for the target audience is likely
just not appropriate.

While cpanm IS technically optional, our belief is that *given our target
audience* the one extra line here is worth it.
Expand section on CPAN

Still incomplete, just incremental step
Add FAQ section

Still needs filling in, just a marker.