corrected typo in comments

src/data_preparation.py

@@ -13,7 +13,7 @@ from typing import Union, List, Iterable
 import datetime as dt
 
 
-# definde more general date type for type hinting
+# define more general date type for type hinting
 date = Union[dt.date, dt.datetime]
 
 
@@ -304,7 +304,7 @@ class DataPrep(object):
         :param coord: name of axis to slice
         :return:
         """
-        return data.loc[{coord: slice(start, end)}]  # type: ignore
+        return data.loc[{coord: slice(start, end)}]
 
     def check_for_negative_concentrations(self, data: xr.DataArray, minimum: int = 0) -> xr.DataArray:
         """