[PATCH 2/2] docs: Rewrite deployment guide

[Finucane, Stephen]

> The existing deployment could do with a little bit of fleshing out.
> Do this, adding notes about the possibility of sidestepping much of
> the process using deployment tools or PaaS solutions.
> 
> This also drops notes on deploying using MySQL/MariaDB or non-Ubuntu
> distros. While it would be good to cover all use cases, it simply
> isn't practical. Do one thing and do it well, providing notes for
> users who want other options.
> 
> Signed-off-by: Stephen Finucane <stephen.finucane at intel.com>
> Suggested-by: Thomas Monjalon <thomas.monjalon at 6wind.com>

Merged.