Update site

[mattbradburyuk]

From customer feedback:

Hello Gowry, Here are some things: • On the top left corner, it's written 2018. • Much of the documentation is still mentioning Corda 3.2. (e.g.: Theon-premise pre-requisites https://solutions.corda.net/deployment/prerequisites-sizing.html) • The documentation has not really been updated recently: https://github.com/corda/corda-solutions/tree/master/docs/source Since it's linked to a team, I assume that it's supported to be somehow maintained. Thanks, Julien

In addition we should add versions to match the corda version.