docs: usb_cdc.Serial.readinto has no nbytes parameter

[Neradoc]

And returns int.

[dhalbert]

Build failure in build-doc is:

Warning, treated as error:
Using the :property: flag with the py:method directiveis deprecated, use ".. py:property::" instead.
Error: Process completed with exit code 2.

[Neradoc]

Wow that has to come from a sphinx related update, I didn't get that locally.
Now when I try to make locally with a fresh venv I get that:

WARNING: Using the :property: flag with the py:method directive is deprecated, use ".. py:property::" instead.
WARNING: Using the :property: flag with the py:method directive is deprecated, use ".. py:property::" instead.
WARNING: Using the :property: flag with the py:method directive is deprecated, use ".. py:property::" instead.
WARNING: Using the :property: flag with the py:method directive is deprecated, use ".. py:property::" instead.

Which is super useful.
When I run ag ":property:" I get these.

shared-bindings/rp2pio/index.rst
282:      :property:
288:      :property:

shared-bindings/sdioio/index.rst
117:      :property:
124:      :property:

These are generated files, so:

//|     @property
//|     def writing(self) -> bool:
//|         """Returns True if a background write is in progress"""
//|

Becomes:

   .. method:: writing(self) -> bool
      :property:

      Returns True if a background write is in progress

I would change it to:

//|     writing: bool
//|     """Returns True if a background write is in progress"""
//|

I can add those changes to this PR, but I get another error in the template, due to sphinx version, I'm curious to see if the CI gets it too.

[Neradoc]

Ok this time the CI does give the same error I get locally:

An error happened in rendering the page BUILDING.
Reason: ValueError('too many values to unpack (expected 3)')

This is a sphinx-rtd-theme issue:
readthedocs/sphinx_rtd_theme#1343

We can temporarily set the sphinx version to 5.1.1

[jepler]

We can temporarily set the sphinx version to 5.1.1

Mind adding that to this PR? If you do please tag me for reviewing.

[Neradoc]

Pushed the workaround:

sphinx!=5.2.0.post0

[jepler]

If this finally builds it's good to merge. I added the 3.10.6 python pin for the doc build

[jepler]

Thanks!