Context-aware navigation (with arrow keys)

[joepio]

I'd like to quickly navigate array-like structures with my keyboard, also after I've opened one item. I think its behavior depends on context.

• When I open an item from the search page, I want to quickly go to the next result
• When I open an item from a collection, I want to quickly go to the next member
• When I open an item from some non-array like structure, I want to open the next item from the parent.