(PUP-500) Clarify that collect with <| |> collects and overrides regular

This clarifies that <| |> operator processes all kinds of resource,
not just those that are virtual, and that it can be used to
override any resource's parameters.
(maint) Fix language after review.
Merge branch 'pr/7'

* pr/7:
  (maint) Fix language after review.
  (PUP-500) Clarify that collect with <| |> collects and overrides regular

Closes #7