clarify that unused host name value should not be changed
Documentation for bosh vSphere CPI.

Signed-off-by: Matthew Boedicker <mboedicker@pivotallabs.com>
Merge pull request #269 from cdavisafc/master

clarify that unused host name value should not be changed
Merge pull request #270 from cloudfoundry/vsphere_cpi

Documentation for bosh vSphere CPI.
fix typos