[gdsii_arrow] add some TODO notes

masque/file/gdsii_arrow.py

@@ -1,5 +1,5 @@
 """
-GDSII file format readers and writers using the `klamath` library.
+GDSII file format readers and writers using the `TODO` library.
 
 Note that GDSII references follow the same convention as `masque`,
   with this order of operations:
@@ -18,6 +18,9 @@ Notes:
  * GDS does not support library- or structure-level annotations
  * GDS creation/modification/access times are set to 1900-01-01 for reproducibility.
  * Gzip modification time is set to 0 (start of current epoch, usually 1970-01-01)
+
+ TODO writing
+ TODO warn on boxes, nodes
 """
 from typing import IO, cast, Any
 from collections.abc import Iterable, Mapping, Callable