Fix merge errors in README
Fix merge errors in README

Between the smoke test docs and Paul's work on the format of prison yaml
files, git got very confused.  A manual collation of the two sections
seemed safer than trying to unpick the spaghetti mess created by the
mergetool.

ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-public,ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-public,ministryofjustice/prison-visits-public,ministryofjustice/prison-visits-2,ministryofjustice/prison-visits-public,ministryofjustice/prison-visits-2