initial typing support, mypy passes

[matt-land]

This adds support for #96

Changes

• adds all types
• modifies rgb.py/color565() to not change types of the r value from tuple to int (mypy assignment and a ton of other errors)
• adds -> read and -> write methods to Display class to (7x mypy attr-defined errors.) They are implemented in the child DisplaySPI class, and if this wasn't Circuitpython, I'm sure it would use abc.Meta. Feedback requested.
• adds a RuntimeError if DisplaySPI->reset() is called, but the reset pin was not defined during init (Mypy attr )
• adds pre-commit hook to the project to run mypy
• trivial optimization to SSD1351, removed a reference for setting baudrate

Testing

pipenv shell
pip install mypy
pip install requirements.txt

mypy adafruit_rgb_display

Success: no issues found in 10 source files