change Zebra page to ZeroCloud only

Content has been changed to remove references to Zebra, revise filename, and setup redirects
Change ZeroCloud page title, Zebra->ZeroCloud
Merge pull request #10 from larsbutler/zebra-zerocloud

Change ZeroCloud page title, Zebra->ZeroCloud
Typo: applicaiton -> application
Merge pull request #11 from Peeja/patch-1

Typo: applicaiton -> application
Massive update to the `download` page

A lot of the instructions are old and out of date. Technically, they
still work, but they're not super relevant for the current state of the
project and the documentation on zerovm.readthedocs.org.