DOC: fix SA01 for pandas.NamedAgg (#59029)

Author: tuhinsharma121

ci/code_checks.sh

@@ -91,7 +91,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         -i "pandas.MultiIndex.to_frame RT03" \
         -i "pandas.NA SA01" \
         -i "pandas.NaT SA01" \
-        -i "pandas.NamedAgg SA01" \
         -i "pandas.Period.asfreq SA01" \
         -i "pandas.Period.freq GL08" \
         -i "pandas.Period.freqstr SA01" \

pandas/core/groupby/generic.py

@@ -124,6 +124,10 @@ class NamedAgg(NamedTuple):
         Function to apply to the provided column. If string, the name of a built-in
         pandas function.
 
+    See Also
+    --------
+    DataFrame.groupby : Group DataFrame using a mapper or by a Series of columns.
+
     Examples
     --------
     >>> df = pd.DataFrame({"key": [1, 1, 2], "a": [-1, 0, 1], 1: [10, 11, 12]})