doc(docstring): improve specificity

Co-authored-by: Robert Bartel <[email protected]>

python/ngen_cal/src/ngen/cal/ngen.py

@@ -131,7 +131,7 @@ def __init__(self, **kwargs):
 
     @staticmethod
     def _is_legacy_gpkg_hydrofabric(hydrofabric: Path) -> bool:
-        """Return True if legacy hydrofabric."""
+        """Return True if legacy (<=v2.1) gpkg hydrofabric."""
         import sqlite3
         connection = sqlite3.connect(hydrofabric)
         # hydrofabric <= 2.1 use 'flowpaths'