Clean up some minor doc errors/formats (#559)

docs/piouart.rst

@@ -29,5 +29,8 @@ A ``SoftwareSerial`` wrapper is included to provide plug-and-play compatibility
 with the Arduino `Software Serial <https://docs.arduino.cc/learn/built-in-libraries/software-serial>`_
 library.  Use the normal ``#include <SoftwareSerial.h>`` to include it.   The following
 differences from the Arduino standard are present:
+
 * Inverted mode is not supported
-* All ports are always listening.  The ``listen`` call is a no-op, and ``isListening()`` always returns ``true`` .
+* All ports are always listening
+* ``listen`` call is a no-op
+* ``isListening()`` always returns ``true``

docs/serial.rst

@@ -32,15 +32,14 @@ using the ``setFIFOSize`` call prior to calling ``begin()``
         Serial1.begin(baud);
 
 The FIFO is normally handled via an interrupt, which reduced CPU load and
-makes it less likely to lose characters.  However, the FIFO introduces up
-to 32 bit-times of delay before serial data is available to the application.
+makes it less likely to lose characters.
 
-For applications where this is an issue (i.e. very low baud), use
+For applications where an IRQ driven serial port is not appropriate, use
 ``setPollingMode(true)`` before calling ``begin()``
 
 .. code:: cpp
         Serial1.setPollingMode(true);
-        Serial1.begin(110)
+        Serial1.begin(300)
 
 For detailed information about the Serial ports, see the
 Arduino `Serial Reference <https://www.arduino.cc/reference/en/language/functions/communication/serial/>`_ .