f-string docs update: the level of expression nesting in format specifiers

PEP 701 said:

Similarly, this PEP leaves up to the implementation the level of expression nesting in format specifiers but specifies a lower bound of 2 levels of nesting. This means that the following should always be valid:
f"{'':*^{1:{1}}}"

However, the docs haven't updated:

BTW, IIUC the specification of f-string has moved from syntax(lexical) to grammar.
Thus, it probably should be moved from https://docs.python.org/3.12/reference/lexical_analysis.html#formatted-string-literals to https://docs.python.org/3.12/reference/grammar.html or https://docs.python.org/3.12/reference/expressions.html#literals. Or a special note should be added.
At least this lexical grammar is outdated and should be removed (or replaced by the PEG grammar):

Empieza comparando PEP 701 con la sección sobre literales de cadena formateados en docs.python.org/3.12/reference/lexical_analysis.html y con las secciones de gramática y expresiones a las que hace referencia. Actualiza la documentación para describir el nivel de anidamiento de expresiones compatible y determina si la gramática léxica obsoleta debe eliminarse, reemplazarse o acompañarse de una nota.