DOC: fix ES01 for pandas.Flags (#57563)

fix ES01 for pandas.Flags

Author: jordan-d-murphy

ci/code_checks.sh

@@ -521,7 +521,6 @@ if [[ -z "$CHECK" || "$CHECK" == "docstrings" ]]; then
         pandas.DatetimeIndex.year\
         pandas.DatetimeTZDtype.tz\
         pandas.DatetimeTZDtype.unit\
-        pandas.Flags\
         pandas.HDFStore.get\
         pandas.HDFStore.info\
         pandas.HDFStore.keys\

pandas/core/flags.py

@@ -11,6 +11,10 @@ class Flags:
     """
     Flags that apply to pandas objects.
 
+    “Flags” differ from “metadata”. Flags reflect properties of the pandas
+    object (the Series or DataFrame). Metadata refer to properties of the
+    dataset, and should be stored in DataFrame.attrs.
+
     Parameters
     ----------
     obj : Series or DataFrame
@@ -30,6 +34,11 @@ class Flags:
            it is expected that every method taking or returning one or more
            DataFrame or Series objects will propagate ``allows_duplicate_labels``.
 
+    See Also
+    --------
+    DataFrame.attrs : Dictionary of global attributes of this dataset.
+    Series.attrs : Dictionary of global attributes of this dataset.
+
     Examples
     --------
     Attributes can be set in two ways: