docs(embedded): say the tags come from coordinode whole

Both packages ship from this repository at one version, so the embedded
package takes the shared tags from coordinode together or defines its own.

Author: polaz

coordinode-embedded/python/coordinode_embedded/_types.py

@@ -17,6 +17,8 @@
 
 from datetime import UTC, datetime, timedelta
 
+# Both packages ship from this repository at one version: the tags come from
+# `coordinode` whole.
 try:  # pragma: no cover - exercised by whichever install shape is in use
     from coordinode._types import MultiVector, Path, Timestamp
 except ImportError: