def in_source_dir(*paths)
      paths.reduce(source) do |base, path|
        Jekyll.sanitized_path(base, path)
      end
    end
def in_source_dir(*paths)
      paths.reduce(source) do |base, path|
        Jekyll.sanitized_path(base, path)
      end
    end
Public: Prefix a given path with the source directory.

 paths - (optional) path elements to a file or directory within the
         source directory

 Returns a path which is prefixed with the source directory.