Update readme

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2020 vieta.app
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,5 +1,18 @@
 # node macOS Sign in With Apple
 
+## Installation
+
+Using Yarn
+```sh
+yarn add node-mac-sign-in-with-apple
+```
+
+Using NPM
+
+```sh
+npm install node-mac-sign-in-with-apple
+```
+
 ## Usage with Electron
 
 Add to main process
@@ -9,10 +22,14 @@ import { signInWithApple } from 'node-mac-sign-in-with-apple';
 
 ipcMain.on('sign-in-with-apple', async () => {
  const nativeWindow = mainWindow.getNativeWindowHandle();
- signInWithApple(nativeWindow);
+ const data = await signInWithApple(nativeWindow);
 })
 ```
 
+> Note: Only on first login Apple returns email and user name, on other requests
+> Apple returns only **idToken**
+
+
 Add to entitlements.plist
 
 ```xml
@@ -21,3 +38,7 @@ Add to entitlements.plist
  <string>Default</string>
 </array>
 ```
+
+## License
+
+The package is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).