Document cell_id inside docs/wrapperkernels.rst

[lucafabbian]

Hi! I tried to implement my own kernel, but I struggled to find a way to identify cells.

That identifier actually exists, but is not documented anywhere inside this page.

Maybe you may change the do_execute signature in the echo example and use this one instead?

    def do_execute(self, code, silent, store_history=True, user_expressions=None,
                   allow_stdin=False, *, cell_id=None):

I think it would be really useful to document better such an important feature.

[c-h-russell-walker]

Hello, I am also hoping to use the cell_id parameter as seen here as part of the ipython 8.3.0 release: https://ipython.readthedocs.io/en/stable/whatsnew/version8.html#ipython-8-3-0

Is there a chance this could be added to this library? Thanks so much.