Describe master-detail view

[swhite2]

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Is your feature request related to a problem? Please describe.

More and more MVC pages are starting to use master-detail grids to describe one-to-many relationships. People tend to get confused about how they work so adding some documentation to the relevant pages would be nice. Another option would be to describe it generally, although it makes more sense that people who encounter this problem will look for an explanation in the relevant section.