explore_release and explore_record are not in-sync

[jpmckinney]

In the explore_additional_content block, explore_record has "Is structurally correct?", "Number of records", etc. which are in the headlines block in explore_release. The record template also has the Schema and Convert boxes alongside the Headlines box, whereas the release template has them beneath.

As much as possible, the two templates should be the same. We should perhaps have each inherit from (or reuse blocks from) a common template.