Update the README.md about SwiftPM support

Author: lizhuoli

Diff for: README.md

@@ -4,6 +4,7 @@
 [![Version](https://img.shields.io/cocoapods/v/SDWebImageFLPlugin.svg?style=flat)](https://cocoapods.org/pods/SDWebImageFLPlugin)
 [![License](https://img.shields.io/cocoapods/l/SDWebImageFLPlugin.svg?style=flat)](https://cocoapods.org/pods/SDWebImageFLPlugin)
 [![Platform](https://img.shields.io/cocoapods/p/SDWebImageFLPlugin.svg?style=flat)](https://cocoapods.org/pods/SDWebImageFLPlugin)
+[![SwiftPM compatible](https://img.shields.io/badge/SwiftPM-compatible-brightgreen.svg?style=flat)](https://swift.org/package-manager/)
 [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/SDWebImage/SDWebImageFLPlugin)
 [![codecov](https://codecov.io/gh/SDWebImage/SDWebImageFLPlugin/branch/master/graph/badge.svg)](https://codecov.io/gh/SDWebImage/SDWebImageFLPlugin)
 
@@ -81,6 +82,18 @@ SDWebImageFLPlugin is available through [Carthage](https://github.com/Carthage/C
 github "SDWebImage/SDWebImageFLPlugin"
 ```
 
+#### Swift Package Manager (Xcode 11+)
+
+SDWebImageFLPlugin is available through [Swift Package Manager](https://swift.org/package-manager).
+
+```swift
+let package = Package(
+    dependencies: [
+        .package(url: "https://github.com/SDWebImage/SDWebImageFLPlugin.git", from: "0.6.0")
+    ]
+)
+```
+
 ## Author
 
 DreamPiggy, [email protected]