Add config files for spec+spec_nb, make output directory parent

swash/processing/swash.py

@@ -25,6 +25,7 @@ out = pathlib.Path(config.get("swash", "out"))
 if out.exists():
     log.error(f"Swash output '{out}' already exists")
     sys.exit(1)
+out.parent.mkdir(parents=True, exist_ok=True)
 
 with tempfile.TemporaryDirectory(prefix="swash_", dir=".") as tmp_raw:
     tmpdir = pathlib.Path(tmp_raw)