Use json5 to parse playbook spec file in JSON format
Internally, convict uses json5 to load JSON data. When Antora took over parsing the JSON data, it switch to the built-in JSON package in Node. As a consequence, support for JSON 5 was lost. JSON 5 adds support for comments, single quoted string values, and unquoted keys to JSON, among other features, making it more friendly as a configuration format. The playbook builder should switch back to using json5 to parse a playbook spec file in JSON format.