Modify docs

README.md

@@ -2,19 +2,43 @@
 
 This package provides a file watcher.
 
-## Usage
+## Installation
+
+The current version only supports [fswatch](https://github.com/emcrisostomo/fswatch), so you'll have to install fswatch first.
+
+```sh
+# MacOS
+brew install fswatch
+
+# Linux (building from Source)
+wget https://github.com/emcrisostomo/fswatch/releases/download/{VERSION}/fswatch-{VERSION}.tar.gz
+tar -xzvf fswatch-{VERSION}.tar.gz
+cd fswatch-{VERSION} && ./configure && make && sudo make install && sudo ldconfig
+```
+
+> A user who wishes to build fswatch should get a release [tarball](https://github.com/emcrisostomo/fswatch/releases)
+
+Then, make sure you have [swoole](https://www.swoole.co.uk/) extension installed in PHP.
+
+```sh
+pecl install swoole
+```
 
-You may install Swoole Unit via Composer:
+Finally, you may install the Swoole Watcher via Composer:
 
 ```sh
-$ composer require huang-yi/swoole-watcher
+composer require huang-yi/swoole-watcher
 ```
 
-Then, create your watcher script.
+## Usage
+
+Create your watcher script like this:
 
 ```php
 <?php
 
+require __DIR__ . '/vendor/autoload.php';
+
 use HuangYi\Watcher\Commands\Fswatch;
 use HuangYi\Watcher\Watcher;
 
@@ -27,16 +51,20 @@ $command->setOptions([
 
 $watcher = new Watcher($command);
 
-$watcher->onChange(function () {
+// Registers a callback for an event.
+$watcher->on(Fswatch::CREATED, function ($path) {
+    // do something...
+});
+
+// or registers a default callback for any event.
+$watcher->onChange(function ($events) {
     // do something...
 });
 
 $watcher->start();
 
 ```
 
-You can stop watch by using `$watcher->stop()`.
-
 ## License
 
-Swoole Unit is open-sourced software licensed under the [MIT license](LICENSE).
+Swoole Watcher is open-sourced software licensed under the [MIT license](LICENSE).