* use Capture Description if available
* update golden/comprehensive.md
This is technically a breaking change, because if a Capture has both a
Description and a ToCapture instance, the Description now takes
precedence. Since this Description wasn't doing anything before, I am
guessing that most projects currently only use Description to describe
their endpoints and not their Captures, and thus that few people will be
affected by this breaking change.
* test the "no ToCapture instance" case
The case in which there is both a Description and a ToCapture instance
seems like a corner case. The more interesting cases are the one in
which there is a Description but no ToCapture instance, and the case in
which there is a ToCapture instance but no description.
