modify readme file add cut notes for #50

Author: lsongdev

README.md

@@ -7,7 +7,7 @@ ESC/POS Printer driver for node
 ## Installation
 
 ````
-$ npm i escpos
+$ npm i escpos --save
 ````
 
 if you use usb as an adapter :
@@ -46,36 +46,24 @@ device.open(function(){
   });
 
 });
-
-
 ````
-----
-## USB Adapter methods
-### open(function calback)
-Claims the current device USB, if the printer is already in use by other process this will fail.
 
-By default, the USB adapter will set the first printer found, if you have multiple printers use `setDevice` and `getDevices` to switch between printers.
+----
 
-Triggers the callback function when done.
 
-### openAll()
-Claims all the printers connected to the machine, one by one. When done, sets the first printer found as the default device and triggers the callback function.
+## USB Adapter methods
 
-### getDevices()
-Returns the number (N) of printers connected, if open is called you must open each device in order to use it.
+### open(function calback)
 
-The ID of the printer will be the number you want to set from 0 to N-1.
+Claims the current device USB, if the printer is already in use by other process this will fail.
 
-### setDevice(N)
-Sets the index passed as the current device, N must be higher than 0 and lower than `getDevices()`.
+By default, the USB adapter will set the first printer found .
 
-This must be called before printing if you want to swtich between multiple printers connected to the same device.
+Triggers the callback function when done.
 
 ### close(function callback)
-Closes the current device and releases its USB interface.
 
-### closeAll(function callback)
-Similar to `close()` but loops through all the devices connected and closes them all.
+Closes the current device and releases its USB interface.
 
 ----
 
@@ -158,6 +146,8 @@ Cut paper.
 mode set a full or partial cut. Default: full
 Partial cut is not implemented in all printers.
 
+*** Don't foget this, because cut will flush buffer to printer ***
+
 ### cashdraw(pin)
 
 Sends a pulse to the cash drawer in the specified pin.