Inter limit fix

fixed (one-off) error with limit higher than 2 (solving #388 (closed))

saqc/funcs/interpolation.py

@@ -144,7 +144,7 @@ class InterpolationMixin:
         method: _SUPPORTED_METHODS,
         order: int = 2,
         limit: int | None = None,
-        downgrade: bool = False,
+        extrapolate: Literal['forward', 'backward', 'both'] = None,
         flag: float = UNFLAGGED,
         **kwargs,
     ) -> "SaQC":
@@ -187,6 +187,7 @@ class InterpolationMixin:
             method,
             order=order,
             gap_limit=limit,
+            extrapolate=extrapolate
         )
 
         interpolated = self._data[field].isna() & inter_data.notna()