Readme formatting

README.md

 # PCF8591 for Micropython
+
 ## Installation
+
 It's actually very simple. Just import upip and install the package.
 
     import upip
     upip.install('micropython-pcf8591')
 
 ## Usage
+
 The PCF8591 class has 4 main public methods available: set_out, set_program, read, write.
 
-###PCF8591:
-####\_\_init\_\_(i2c, addr=..., enable_out=..., in_program=...):
+### PCF8591:
+
+#### \_\_init\_\_(i2c, addr=..., enable_out=..., in_program=...):
+
 _Initializes the instance_
+
 - **i2c** is a Micropython I2C instance
 - **addr** is the address of the device, defaults to 72 (0x48).
 - **enable_out** is for setting "ANALOG OUTPUT ENABLE FLAG". Also enables the internal oscillator which is a must for auto-increment. Valid options are: (`True`, `False`). Defaults to `True`.
 - **in_program** is for settings "ANALOG INPUT PROGRAMMING". Valid options are: (`AINPRG0`, `AINPRG1`, `AINPRG2`, `AINPRG3`). Defaults to `AINPRG0`.
 
-####set_out(enable_out):
+#### set_out(enable_out):
+
 _Sets the output flag_
+
 - **enable_out** is for setting "ANALOG OUTPUT ENABLE FLAG". Also enables the internal oscillator which is a must for auto-increment. Valid options are: (`True`, `False`).
 
-####set_program(in_program):
+#### set_program(in_program):
+
 _Sets the input program_
+
 - **in_program** is for settings "ANALOG INPUT PROGRAMMING". Valid options are: (`AINPRG0`, `AINPRG1`, `AINPRG2`, `AINPRG3`).
 
-####read(channel=...):
+#### read(channel=...):
+
 _Reads analog data from the device. When auto incrementing is enabled, this function will return all four inputs as a list, otherwise returns a single integer._
+
 - **channel** is for setting the "A/D CHANNEL NUMBER". When is None, auto incrementing will be enabled. Valid options are(`ACHNNL0`, `ACHNNL1`, `ACHNNL2`, `ACHNNL3`, `None`). Defaults to `None`.
 
-####write(value):
+#### write(value):
+
 _Writes analog data to the device. It'll automatically enable analog out._
+
 - **value** is for setting the analog output value of the device. Valid options are: (`0-255`)
 
-###Constants
+### Constants
+
 - **AINPRG0**: ANALOG INPUT PROGRAM 0
 - **AINPRG1**: ANALOG INPUT PROGRAM 1 
 - **AINPRG2**: ANALOG INPUT PROGRAM 2
@@ -43,6 +58,7 @@ _Writes analog data to the device. It'll automatically enable analog out._
 - **ACHNNL3**: ANALOG CHANNEL 3
 
 ## Development
+
 As you can guess, there are no tests whatsoever, no coverage, nothing!
 You can create a distribution package by running this command inside pcf8591 directory.