docs: Remove trailing spaces and convert tabs to spaces.

Signed-off-by: Damien George <damien@micropython.org>

docs/pyboard/quickref.rst

@@ -225,20 +225,20 @@ I2S bus
 See :ref:`machine.I2S <machine.I2S>`. ::
 
     from machine import I2S, Pin
-    
+
     i2s = I2S(2, sck=Pin('Y6'), ws=Pin('Y5'), sd=Pin('Y8'), mode=I2S.TX, bits=16, format=I2S.STEREO, rate=44100, ibuf=40000) # create I2S object
     i2s.write(buf)             # write buffer of audio samples to I2S device
-    
+
     i2s = I2S(1, sck=Pin('X5'), ws=Pin('X6'), sd=Pin('Y4'), mode=I2S.RX, bits=16, format=I2S.MONO, rate=22050, ibuf=40000) # create I2S object
     i2s.readinto(buf)          # fill buffer with audio samples from I2S device
-    
-The I2S class is currently available as a Technical Preview.  During the preview period, feedback from 
+
+The I2S class is currently available as a Technical Preview.  During the preview period, feedback from
 users is encouraged.  Based on this feedback, the I2S class API and implementation may be changed.
 
-PYBv1.0/v1.1 has one I2S bus with id=2.  
-PYBD-SFxW has two I2S buses with id=1 and id=2.  
-I2S is shared with SPI.  
-    
+PYBv1.0/v1.1 has one I2S bus with id=2.
+PYBD-SFxW has two I2S buses with id=1 and id=2.
+I2S is shared with SPI.
+
 CAN bus (controller area network)
 ---------------------------------
 

docs/pyboard/tutorial/accel.rst

@@ -29,7 +29,7 @@ We will start by using the accelerometer to turn on a light if it is not flat. :
 
     while True:
         x = accel.x()
-        if abs(x) > SENSITIVITY: 
+        if abs(x) > SENSITIVITY:
             light.on()
         else:
             light.off()
@@ -61,7 +61,7 @@ use the ``y()`` value and more LEDs we can turn the pyboard into a spirit level.
 
     while True:
         x = accel.x()
-        if x > SENSITIVITY: 
+        if x > SENSITIVITY:
             xlights[0].on()
             xlights[1].off()
         elif x < -SENSITIVITY:
@@ -72,7 +72,7 @@ use the ``y()`` value and more LEDs we can turn the pyboard into a spirit level.
             xlights[1].off()
 
         y = accel.y()
-        if y > SENSITIVITY: 
+        if y > SENSITIVITY:
             ylights[0].on()
             ylights[1].off()
         elif y < -SENSITIVITY:

docs/pyboard/tutorial/leds.rst

@@ -47,7 +47,7 @@ Here, n keeps track of the current LED and every time the loop is executed we cy
 One problem you might find is that if you stop the script and then start it again that the LEDs are stuck on from the previous run, ruining our carefully choreographed disco. We can fix this by turning all the LEDs off when we initialise the script and then using a try/finally block. When you press CTRL-C, MicroPython generates a VCPInterrupt exception. Exceptions normally mean something has gone wrong and you can use a try: command to "catch" an exception. In this case it is just the user interrupting the script, so we don't need to catch the error but just tell MicroPython what to do when we exit. The finally block does this, and we use it to make sure all the LEDs are off. The full code is::
 
     leds = [pyb.LED(i) for i in range(1,5)]
-    for l in leds: 
+    for l in leds:
         l.off()
 
     n = 0

docs/pyboard/tutorial/repl.rst

@@ -73,7 +73,7 @@ indicate that you should type the text after it at the prompt.  In the end, once
 you have entered the text ``print("hello pyboard!")`` and pressed Enter, the output
 on your screen should look like it does above.
 
-If you already know some python you can now try some basic commands here. 
+If you already know some python you can now try some basic commands here.
 
 If any of this is not working you can try either a hard reset or a soft reset;
 see below.

docs/pyboard/tutorial/reset.rst

@@ -21,7 +21,7 @@ To enter safe mode, do the following steps:
 4. The LEDs will then cycle green to orange to green+orange and back again.
 5. Keep holding down USR until *only the orange LED is lit*, and then let
    go of the USR switch.
-6. The orange LED should flash quickly 4 times, and then turn off.  
+6. The orange LED should flash quickly 4 times, and then turn off.
 7. You are now in safe mode.
 
 In safe mode, the ``boot.py`` and ``main.py`` files are not executed, and so