Update Readme with new instructions to install the package with SPM

README.md

@@ -27,15 +27,13 @@ pod try CalendarKit
 
 
 ## Installation
-### Swift Package Manager (Xcode 11 or higher)
+### Swift Package Manager (Xcode 12 or higher)
 
 The preferred way of installing CalendarKit is via the [Swift Package Manager](https://swift.org/package-manager/).
 
->Xcode 11 integrates with libSwiftPM to provide support for iOS, watchOS, and tvOS platforms.
-
 1. In Xcode, open your project and navigate to **File** → **Swift Packages** → **Add Package Dependency...**
 2. Paste the repository URL (`https://github.com/richardtop/CalendarKit.git`) and click **Next**.
-3. For **Rules**, select **Branch** (with branch set to `master`).
+3. For **Rules**, select **Version (Up to Next Major)** and click **Next**.
 4. Click **Finish**.
 
 A more detailed guide can be found here: [Adding Package Dependencies to Your App](https://developer.apple.com/documentation/swift_packages/adding_package_dependencies_to_your_app)