Create a CF Provider Page on cloudfoundry.org

[beyhan]

There was an ask in this Slack discussion to have a page where the CF providers are listed so that people can find options to try CF. During the TOC meeting on 27th of May we decided to put this information on cloudfoudnry.org and link to it from the CF docs. This is a tracking issue for that effort.

Tasks:

• Add try cf page to let potential customers freely play with CF without installation docs-dev-guide#558