Only show headers when available
Better request/response body generation

- If HAL is detected, generate HAL response bodies. If the request is a
  collection, ensure a HAL collection type is generated.
- Ensure links are generated properly as well.
Rebuilt distribution
Merge branch 'hotfix/docs-ui-improvements'

Conditional display of headers in documentation.
Generation of request/response payloads should take into account whether or not
HAL might be expected, and generate HAL payloads.