Create an `ItemList` in `path` from the filenames that have a suffix in `extensions`.
        `recurse` determines if we search subfolders.

def from_folder(cls, path:PathOrStr, extensions:Collection[str]=None, recurse:bool=True,
                    include:Optional[Collection[str]]=None, processor:PreProcessors=None, **kwargs)->'ItemList':
        """Create an `ItemList` in `path` from the filenames that have a suffix in `extensions`.
        `recurse` determines if we search subfolders."""
        path = Path(path)
        return cls(get_files(path, extensions, recurse=recurse, include=include), path=path, processor=processor, **kwargs)