Feature summary: I would like to easily see the numeric identifier of a property listed in the AboutTopic special page of ArticlePlaceholder

Steps to reproduce:

• Call the special page for a specific item on a linked Wikibase instance, like Special:AboutTopic/Q64
• Properties are listed in boxes:
  • the name of the property (like Some property) is an <h2> element
  • the number of the property (like P12) is not shown

Use case(s) : Seeing the actual property number is useful for a number of reason, for instance for debugging LUA modules or templates that are acting of Wikibase data. It also provides the reader with more information.

Proposed solution : The more unobtrusive, but still easily accessible, way to do this is to set the title property of the <h2> so a tooltip is shown.