Move bootstrap.sh to root and create root symlink activate.sh
(pointing to bootstrap.sh).
Create symlinks to these files from inside pw_env_setup (to be
removed once recipes are updated).
Change-Id: I163d726402dd543d13b28cd5c7d066841dd93138
Trims setup information out of the README.md, and pushes setup and
developer guides into their own pages.
Change-Id: I7fc80213e6a00c270fc9c664c8a7f54a19c05778