Add note about possible deprecation

Signed-off-by: Juan Luis Cano Rodríguez <[email protected]>

kedro/framework/cli/utils.py

@@ -64,6 +64,7 @@ def python_call(
 
 
 def find_stylesheets() -> Iterable[str]:  # pragma: no cover
+    # TODO: Deprecate this function in favour of kedro-sphinx-theme
     """Fetch all stylesheets used in the official Kedro documentation"""
     css_path = Path(__file__).resolve().parents[1] / "html" / "_static" / "css"
     return (str(css_path / "copybutton.css"),)