DOC: correct min_count param docstring (#19836)

Author: ZhuBaohe

pandas/core/generic.py

@@ -7855,7 +7855,7 @@ def _doc_parms(cls):
 >>> pd.Series([np.nan]).prod()
 1.0
 
->>> pd.Series([np.nan]).sum(min_count=1)
+>>> pd.Series([np.nan]).prod(min_count=1)
 nan
 """
 
@@ -7867,8 +7867,9 @@ def _doc_parms(cls):
 
     .. versionadded :: 0.22.0
 
-       Added with the default being 1. This means the sum or product
-       of an all-NA or empty series is ``NaN``.
+       Added with the default being 0. This means the sum of an all-NA
+       or empty Series is 0, and the product of an all-NA or empty
+       Series is 1.
 """