Update README.md

Author: ActuallyTaylor

README.md

@@ -41,7 +41,7 @@ Don't forget to alter your Carthage [building phase for macOS](https://github.co
 To integrate SystemKit int your Xcode project using SPM, add the following to your Swift.package
 
 ```
-  .package(url: "https://github.com/impel-intelligence/SystemKit/", branch: "master")
+  .package(url: "https://github.com/impel-intelligence/SystemKit/", branch: "main")
 ```
 
 Or you can just add[ [https://github.com/impel-intelligence/SystemKit/](https://github.com/impel-intelligence/SystemKit/) to your project using the Xcode Package Dependencies Page.