Add doc entry, add example and fix missing support for multi-1D LUT.

Author: MichaelMauderer

colour_clf_io/__init__.py

@@ -104,7 +104,7 @@
 __version__ = f"{__major_version__}.{__minor_version__}.{__change_version__}"
 
 
-def read_clf(path: str | Path) -> ProcessList | None:
+def read_clf(path: str | Path) -> ProcessList:
     """
     Read given *CLF* file and return a *ProcessList*.