Clean up broken links and fix commands in "Getting started locally"
Clean up broken links and fix commands in "Getting started locally"

Update required versions, fix a bunch of broken links, and generally normalize the way shell commands are referred to. In addition, stop assuming that anybody has `.` in their `$PATH` in recommended shell commands.

Note that I recorded many of these issues in a friction log (https://docs.google.com/document/d/18741pdPn74ykHODEcX11fS21rU3GpJM30yBbcP1akUk/edit?usp=sharing).

kubernetes/community,kubernetes/community,pwittrock/community,pwittrock/community,kubernetes/community