While the linux dependency is obvious with a moment's thought, some
users (especially on *nix) might plow ahead before realizing their
system isn't supported. This adds a requirements section and points
users in the direction of guides more likely to work for them.
Building kubecfg is required for kubecfg.sh. kubecfg.sh will warn
of this if it hasn't been built, but it's a better user experience
to make people explicitly aware of all required steps.
The project README is getting quite large mainly because of all
the getting started guides embedded in the README.
Create the docs/getting-started-guides directory and relocate all
getting started guides. Update the README to link to each getting
started guide.
