Extend "About" page with catalog policies

[dgarijo]

We should be able to answer the following questions in an additional help page:

• What is the schema used to define data?
• Can records be queried?
• How can users modify records?
• Who owns the records?
• What is the retention policy?
  We should have templates for some of these. And we should be able to read this from the config of the tool when the catalog is generated. Based on https://peerj.com/articles/cs-1023/#p-27