added new entry for cache changing

Author: anmyachev

pandas/core/tools/datetimes.py

@@ -534,7 +534,11 @@ def to_datetime(arg, errors='raise', dayfirst=False, yearfirst=False,
         conversion. May produce significant speed-up when parsing duplicate
         date strings, especially ones with timezone offsets.
 
-        .. versionchanged:: 0.25.0
+        .. versionadded:: 0.25.0
+
+        cache : boolean, default False
+
+            .. versionadded:: 0.23.0
 
     Returns
     -------