Update readme with chat room docs and stop a warning.

Author: tannewt

README.rst

@@ -5,6 +5,14 @@ Adafruit CircuitPython BusDevice
  :target: https://circuitpython.readthedocs.io/projects/bus_device/en/latest/
  :alt: Documentation Status
 
+.. image :: https://badges.gitter.im/adafruit/circuitpython.svg
+ :target: https://gitter.im/adafruit/circuitpython?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge
+ :alt: Gitter
+
+.. image :: https://img.shields.io/discord/327254708534116352.svg
+ :target: https://adafru.it/discord
+ :alt: Discord
+
 The `I2CDevice` and `SPIDevice` helper classes make managing transaction state
 on a bus easy. For example, they manage locking the bus to prevent other
 concurrent access. For SPI devices, it manages the chip select and protocol
@@ -22,7 +30,7 @@ bundle <bundle_installation>`.
 To install:
 
 #. Download and unzip the `latest release zip <https://github.com/adafruit/Adafruit_CircuitPython_BusDevice/releases>`_.
-#. Copy the unzipped `adafruit_bus_device` to the ``lib`` directory on the ``CIRCUITPY`` or ``MICROPYTHON`` drive.
+#. Copy the unzipped ``adafruit_bus_device`` to the ``lib`` directory on the ``CIRCUITPY`` or ``MICROPYTHON`` drive.
 
 API
 ---