SWF support three URI schemes for resolving external resources locations: http(s), file and classpath.
If no scheme is specified, classpath is assumed., which is more less good for resources relative to workflow file (because worklfow file is normally located at the root of the classpath)
Although possible, using file scheme for relative path is cumbersome, therefore, the proposal is to add a new default scheme to be used for path relative to the current file, which will work for workflow files, json schema and open api (the latter already works this way)