DOC: Only include numpy.std() note for std(), not all ddof

Author: TheNeuralBit

pandas/core/generic.py

@@ -10557,6 +10557,7 @@ def mad(self, axis=None, skipna=None, level=None):
             name1=name1,
             name2=name2,
             axis_descr=axis_descr,
+            notes="",
         )
         def sem(
             self,
@@ -10578,6 +10579,7 @@ def sem(
             name1=name1,
             name2=name2,
             axis_descr=axis_descr,
+            notes="",
         )
         def var(
             self,
@@ -10600,6 +10602,7 @@ def var(
             name1=name1,
             name2=name2,
             axis_descr=axis_descr,
+            notes=_std_notes,
         )
         def std(
             self,
@@ -11091,6 +11094,10 @@ def _doc_params(cls):
 Returns
 -------
 {name1} or {name2} (if level specified)
+{notes}
+"""
+
+_std_notes = """
 
 Notes
 -----