DOC: Enforce Numpy Docstring Validation for pandas.Index.fillna (#58417)

* DOC: add RT03 to pandas.Index.fillna

* DOC: remove pandas.Index.fillna

Author: tuhinsharma121

ci/code_checks.sh

@@ -124,7 +124,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         -i "pandas.Index.dropna RT03,SA01" \
         -i "pandas.Index.duplicated RT03" \
         -i "pandas.Index.empty GL08" \
-        -i "pandas.Index.fillna RT03" \
         -i "pandas.Index.get_indexer PR07,SA01" \
         -i "pandas.Index.get_indexer_for PR01,SA01" \
         -i "pandas.Index.get_indexer_non_unique PR07,SA01" \

pandas/core/indexes/base.py

@@ -2578,6 +2578,7 @@ def fillna(self, value):
         Returns
         -------
         Index
+           NA/NaN values replaced with `value`.
 
         See Also
         --------