fix attribute list and NOTSET description in docs

[FoamyGuy]

This tweak to the attribute list syntax allows them to get drawn with more visual seperation on the final docs page.

The current docs page looks like this:

The version with these changes looks like this:

[FoamyGuy]

The latest commit updates the description for NOTSET to more closely match the CPython documentaiton here: https://docs.python.org/3/library/logging.html#logging.Handler.setLevel

NOTSET: int
        The NOTSET logging level, which is the default logging level that can be
        used to indicate that a `Logger` should process any logging messages,
        regardless of how severe those messages are.

Our previous description of this level value was essentially opposite of what CPython docs specify. (Suppress all log messages, rather than process all log messages).

As far as I can tell the currently library behavior does match the CPython description of processing all messages regardless of level.

import adafruit_logging as logging

logger = logging.getLogger("test")
print_logger = logging.StreamHandler()
logger.addHandler(print_logger)
logger.setLevel(logging.NOTSET)

logger.info("Info message\n")
logger.error("Error message\n")

output:

5645.131: INFO - Info message
5645.131: ERROR - Error message

This change is meant to resolve #35

[tekktrik]

Makes sense, great catch!