docs: Clarification of some installation and config steps

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/example.cfg

@@ -5,10 +5,9 @@
 # FIRST. Incorrectly configured parameters may cause damage.
 
 # A note on pin names: pins may be configured with a hardware name
-# (such as PA4) or with a board name (such as ar29). In order to use a
-# board name, the pin_map variable in the mcu section must specify
-# which board definition to use. (See the klippy/pins.py file for the
-# available pin and board names.)
+# (such as "PA4") or with an Arduino alias name (such as "ar29" or
+# "analog3"). In order to use Arduino names, the pin_map variable in
+# the mcu section must be present and have a value of "arduino".
 # Pin names may be preceded by an '!' to indicate that a reverse
 # polarity should be used (eg, trigger on low instead of high). Input
 # pins may be preceded by a '^' to indicate that a hardware pull-up
@@ -173,10 +172,10 @@ kick_start_time: 0.100
 [mcu]
 serial: /dev/ttyACM0
 #   The serial port to connect to the MCU
-baud: 115200
+baud: 250000
 #   The baud rate to use
 pin_map: arduino
-#   This option may be used to add board specific pin name aliases
+#   This option may be used to enable Arduino pin name aliases
 custom:
 #   This option may be used to specify a set of custom
 #   micro-controller commands to be sent at the start of the

docs/Installation.md

@@ -115,7 +115,9 @@ Under "Serial Connection" in "Additional serial ports" add
 "/tmp/printer". Then click "Save".
 
 Enter the Settings tab again and under "Serial Connection" change the
-"Serial Port" setting to "/tmp/printer".
+"Serial Port" setting to "/tmp/printer". Change the Baudrate field to
+250000 (this buad rate field is not related to the firmware baudrate
+and may be safely left at 250000).
 
 Under the "Features" tab, unselect "Enable SD support". Then click
 "Save".