Adafruit-circuitpython-pcf8591

**Full Changelog**: https://github.com/adafruit/Adafruit_CircuitPython_PCF8591/compare/1.0.18...1.0.19

Changes: https://github.com/adafruit/Adafruit_CircuitPython_PCF8591/compare/1.0.17...1.0.18

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-pcf8591`.

Read the [docs](https://circuitpython.readthedocs.io/projects/pcf8591/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-pcf8591`.

Read the [docs](https://circuitpython.readthedocs.io/projects/adafruit-circuitpython-pcf8591/en/latest/) for info on how to use it.

This release includes fixes for some of the typing annotations. Thank you tekktrik.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-pcf8591`.

Read the [docs](http://circuitpython.readthedocs.io/projects/pcf8591/en/latest/) for info on how to use it.

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-pcf8591`.

Read the [docs](http://circuitpython.readthedocs.io/projects/pcf8591/en/latest/) for info on how to use it.

Added type annotations for this library, as well as fixed issues regarding Sphinx documentation formatting. Thanks tcfranks!

To use in CircuitPython, simply install the [Adafruit CircuitPython Bundle](https://circuitpython.org/libraries).

To use in CPython, `pip3 install adafruit-circuitpython-pcf8591`.

Read the [docs](http://circuitpython.readthedocs.io/projects/pcf8591/en/latest/) for info on how to use it.