Apply suggestions from code review

Co-authored-by: Petr Viktorin <encukou@gmail.com>

Author: sobolevn

Doc/c-api/dict.rst

@@ -517,6 +517,12 @@ Dictionary objects
    Clears the input *dict* on success.
    Returns ``NULL`` with the exception set on error.
 
+   This function is intended for building a :class:`!frozendict` instance via
+   a temporary *dict* that is not exposed to user code.
+   To "freeze" an arbitrary dictionary, for example one received from the user
+   as an argument, prefer :c:func:`PyFrozenDict_New` to leave the source
+   intact.
+
    .. impl-detail::
 
       Works with O(1) complexity.

Doc/whatsnew/3.16.rst

@@ -1377,8 +1377,8 @@ C API changes
 New features
 ------------
 
-* Add a new way to efficitly create :class:`frozendict` instance
-  from existing :class:`dict` instances: :c:func:`PyDict_AsFrozenDictAndClear`.
+* Add a new way to efficiently create a :class:`frozendict` instance by building
+  a :class:`dict` and "freezing" it: :c:func:`PyDict_AsFrozenDictAndClear`.
   (Contributed by Nikita Sobolev in :gh:`153413`.)
 
 * Add :c:func:`Py_HashBuffer` to the limited C API.