updated README

README.md

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+# GPIO Controller for Node.js done right
+Intuitive, fun to use, object-oriented implementation. 
+
+Thanks to C++ bindings this package is using kernel level GPIO access via libgpiod (see https://kernel.googlesource.com/pub/scm/libs/libgpiod/libgpiod/+/v0.2.x/README.md). The library offers accuracy and reliability. It can also register changes as quick as 1 microsecond or less and does not require extensive pooling. 
+
+Written in TypeScript.
+
+# Installation
+```sh
+sudo apt update
+sudo apt-get install libgpiod-dev
+yarn add gpiod-client
+```
+
+# API Reference
+  https://kodmax.github.io/gpiod-client/classes/GPIOController.html
+
+# Digital Input
+## Features
+ - reading current value
+ - listening for input events: rising and/or falling edge
+ - nanoseconds precision for each event provided by linux kernel
+ - software input debouncer for ease of using with mechanical switches
+ - configurable 'hold' event triggered after each hold time is reached
+## Polling interval
+### Linux kernel
+The input events are collected at kernel level. Each event has a high resolution timer timestamp attached. The precision goes to nanoseconds level.
+### Input line configuration
+Each input line can be configured with different pooling interval to read those events. Regardless of the pooling interval the precision remains the same and no events are lost.
+If edge events are not needed, no pooling is required.
+## Examples
+### Logging button events
+```ts
+import { GPIOController } from 'gpiod-client'
+
+const gpio = new GPIOController('gpiochip0', 'input27')
+
+// look for both falling and rising edges
+// read the events queue from linux kernel every 100ms
+const line2 = gpio.requestLineAsInput(2, 'both', 100) 
+
+// debounce the mechanical switch noise for 50ms
+// trigger a hold event after 300ms press and then after 1 second press
+const button = line2.createDebouncer(50, 0, [300, 1000]) 
+
+console.log('Hit the button!')
+
+button.addListener('press', () => {
+    console.log('press')
+})
+
+button.addListener('release', () => {
+    console.log('release')
+})
+
+button.addListener('hold', ev => {
+    console.log('hold', ev.time, 'ms')
+})
+```
+# Digital output
+## Features
+ - setting a value
+ - optionally pausing program execution after setings a value (sleep in microseconds). Convenient if the connected circuit needs some microseconds to process the input change
+ - sending an impulse (trigger in microseconds) of 0 or 1. Convenient for triggering RST or other functions.
+
+## Examples
+### Classic, blink as led by settings 0 and 1 in interval of 50 miliseconds
+```ts
+import { GPIOController } from 'gpiod-client'
+
+const gpio = new GPIOController('gpiochip0', 'blink17')
+const led = gpio.requestLineAsOutput(17, 1)
+
+let i = 0
+setInterval(() => {
+    led.setValue(++i % 2 ? 1 : 0)
+}, 50)
+```
+### Flash led for 10 miliseconds every second using trigger
+```ts
+import { GPIOController } from 'gpiod-client'
+
+const gpio = new GPIOController('gpiochip0', 'blink17')
+const led = gpio.requestLineAsOutput(17, 0)
+
+setInterval(() => {
+    led.trigger(1, 10000)
+}, 1000)
+```