Get the full resource list of markdown filesSource:
Get the full resource list of markdown files
path to the lesson
TRUE, trim the paths to be relative to the lesson directory. Defaults to
FALSE, which will return the absolute paths
the subfolder to check. If this is
NULL, all folders will checked and returned (default), otherwise, this should be a string specifying the folder name in the lesson (e.g. "episodes").
subfolder = "episodes", a message is issued to the user if the episodes field of the configuration file is empty.