* Don't include a full path from the build system
* Rename all packages to "foo-stubs"
* Don't install stubs for standard packages like "os"
After this, I can `python setup.py install --user` to install the stubs
to my local environment, and successfully check code against the stubs,
such as
```
/$ mypy -c 'import busio; b: busio.I2C; b.readfrom_into(0x30, b"")'
<string>:1: error: Argument 2 to "readfrom_into" of "I2C" has incompatible type "bytes"; expected "Union[bytearray, memoryview, array[Any], ndarray, RGBMatrix]"
Found 1 error in 1 file (checked 1 source file)
```
The structure of a wheel built with `python setup.py bdist_wheel` looks
more like lxml-stubs, as well.
```
Archive: dist/circuitpython_stubs-7.0.0a3.dev28+g124c7b785-py3-none-any.whl
Length Date Time Name
--------- ---------- ----- ----
30705 2021-06-10 13:50 _bleio-stubs/__init__.pyi…
```
Finally, by eliminating `site.getsitepackages()`, this **may** fix
the doc building problem on readthedocs.
foamyguy
Jeff Epler
Diego Elio Pettenò
Scott Shawcroft
John Reese