Update README: SPM as primary install method, remove deprecated package managers

- Add Swift Package Manager installation instructions as the recommended method
- Remove Carthage and CocoaPods sections (CocoaPods is sunsetting)
- Remove CocoaPods badge
- Simplify demo project instructions

Author: pavankataria

README.md

@@ -18,9 +18,6 @@ https://img.shields.io/cocoapods/p/SwiftDataTables.svg
 <a href="https://swift.org/package-manager">
         <img src="https://img.shields.io/badge/SPM-compatible-brightgreen.svg?style=flat" alt="SPM Compatible" />
     </a>
-   <a href="https://cocoapods.org/pods/SwiftDataTables">
-        <img src="https://img.shields.io/badge/Cocoapods-compatible-4BC51D.svg?style=flat" />
-    </a>
    <a href="https://en.wikipedia.org/wiki/MIT_License">
         <img src="https://img.shields.io/badge/License-MIT-brightgreen.svg?style=flat" />
    </a>
@@ -63,28 +60,28 @@ https://img.shields.io/cocoapods/p/SwiftDataTables.svg
 
 ## Install
 
-### [Carthage](https://github.com/Carthage/Carthage)
-
-- Add the following to your Cartfile: `github "pavankataria/SwiftDataTables"`
-- Then run `carthage update`
-- Follow the current instructions in [Carthage's README][carthage-installation]
-for up to date installation instructions.
+### Swift Package Manager (Recommended)
 
-[carthage-installation]: https://github.com/Carthage/Carthage#adding-frameworks-to-an-application
+Add SwiftDataTables to your project via Xcode:
+1. File → Add Package Dependencies...
+2. Enter the repository URL: `https://github.com/pavankataria/SwiftDataTables`
+3. Select your version rules and add to your target
 
-### [CocoaPods](http://cocoapods.org)
+Or add it to your `Package.swift`:
 
-- Add the following to your [Podfile](http://guides.cocoapods.org/using/the-podfile.html): `pod 'SwiftDataTables'`
-- You will also need to make sure you're opting into using frameworks: `use_frameworks!`
-- Then run `pod install`.
+```swift
+dependencies: [
+    .package(url: "https://github.com/pavankataria/SwiftDataTables", from: "0.9.0")
+]
+```
 
 ## Demo Project Included
 
 To run the example project do the following:
 1. Download or clone the repo (`git clone https://github.com/pavankataria/SwiftDataTables`)
-2. Change directory into the `DemoSwiftDataTables/Example` folder (`cd SwiftDataTables/Example`)
-4. With Xcode 9 installed, as normal, open the `SwiftDataTables.xcodeproj` project
-5. Build and Run.
+2. Open the `SwiftDataTables.xcodeproj` project in Xcode
+3. Select the `DemoSwiftDataTables` scheme
+4. Build and Run
 
 If you have any questions or wish to make any suggestions, please open an issue with the appropriate label, and I'll get back to you right away. Thank you