Merge pull request adafruit#2546 from deshipu/patch-1

Update CircuitPython differences in README

Author: tannewt

README.rst

@@ -94,13 +94,12 @@ Differences from `MicroPython <https://github.com/micropython/micropython>`__
 
 CircuitPython:
 
--  includes ports for MicroChip SAMD21 (Commonly known as M0 in Adafruit
-   product names) and SAMD51 (M4).
--  supports only SAMD21, SAMD51, and nRF52840 ports.
--  tracks MicroPython's releases (not master).
--  floats (aka decimals) are enabled for all builds.
--  error messages are translated into 10+ languages.
--  does not support concurrency within Python (including interrupts and threading). Some concurrency
+-  Supports native USB on all boards, allowing file editing without special tools.
+-  Supports only SAMD21, SAMD51, nRF52840, CXD56, STM32F4 and i.MX RT ports.
+-  Tracks MicroPython's releases (not master).
+-  Floats (aka decimals) are enabled for all builds.
+-  Error messages are translated into 10+ languages.
+-  Does not support concurrency within Python (including interrupts and threading). Some concurrency
    is achieved with native modules for tasks that require it such as audio file playback.
 
 Behavior