###CHANGELOG
- use node v12 and up
- use the first item in operation.consume and produce as the default content-type and response-type respectively
- add support for application/xml response type with formatted response body
- use the global consumes/produces definition if an operation doesn't specify its own
- use ng-bind-html for descriptions to support html syntax, this requires ngSanitize module
- add support for $ref definition on operation parameters
- use bootstrap less only, to remove dependency from bootstrap js and jquery