chore: support cocoapods

ApolloCombine.podspec

@@ -0,0 +1,23 @@
+Pod::Spec.new do |s|
+  s.name             = 'ApolloCombine'
+  s.version          = '0.3.1'
+  s.author           = { 'Joel Perry' => '[email protected]' }
+  s.homepage         = 'https://github.com/joel-perry/ApolloCombine'
+  s.license          = { :type => 'MIT', :file => 'LICENSE' }
+
+  s.summary          = 'A collection of Combine publishers for the Apollo iOS client.'
+
+  s.source           = { :git => 'https://github.com/joel-perry/ApolloCombine.git', :tag => s.version.to_s }
+
+  s.ios.deployment_target = '13.0'
+  s.osx.deployment_target = '10.15'
+  s.tvos.deployment_target = '13.0'
+  s.watchos.deployment_target = '6.0'
+
+  s.source_files = 'Sources/ApolloCombine/*.swift'
+
+  s.weak_frameworks = 'SwiftUI', 'Combine'
+  s.dependency 'Apollo/Core', '>=0.34.0'
+  s.swift_version = '5.2'
+
+end

README.md

@@ -62,5 +62,12 @@ watchSubscription.cancel()
 ### Swift Package Manager
 The [Swift Package Manager](https://swift.org/package-manager/) is a tool for automating the distribution of Swift code and is integrated into the `swift` compiler. Use Xcode’s Swift Packages option, which is located within the File menu.
 
+### CocoaPods
+ApolloCombine is available through [CocoaPods](https://cocoapods.org/). To install it, simply add the following line in your `Podfile`
+
+```
+pod 'ApolloCombine'
+```
+
 ## License
 ApolloCombine is released under the MIT license. [See LICENSE](LICENSE) for details.