Is your feature request related to a problem? Please describe.
The openapi2jolie tool generates Jolie interfaces from OpenAPI specifications. As stated in the documentation of the tool it should take the specification file in input (since there is no specified extension then I guess it'd be both yaml and json) and generate the Jolie interface.
But it works only with JSON files (and not completely well, see #295 for this matter).

Describe the solution you'd like
The tool should be able to convert both YAML and JSON files.

Describe alternatives you've considered
Since json files are already supported I think it would be enough to convert yaml files temporarily to json and then parse them.

Additional context
None.