🍏 Add Cocoapods support with AppcuesNotificationService.podspec

AppcuesNotificationService.podspec

@@ -0,0 +1,22 @@
+# To validate: `$ pod lib lint AppcuesNotificationService.podspec
+
+Pod::Spec.new do |s|
+  s.name             = 'AppcuesNotificationService'
+  s.version          = '0.1.0'
+  s.summary          = 'Provide rich push notifications via Appcues'
+
+  s.description      = <<-DESC
+A Swift library for providing rich push notifications via Appcues.
+                      DESC
+
+  s.homepage         = 'https://github.com/appcues/appcues-ios-sdk'
+  s.license          = { :type => 'MIT', :file => 'LICENSE' }
+  s.author           = { 'Appcues' => '[email protected]' }
+  s.source           = { :git => 'https://github.com/appcues/appcues-ios-sdk.git', :tag => s.version.to_s }
+
+  s.swift_version = '5.0'
+  s.ios.deployment_target = '11.0'
+
+  s.source_files = 'Sources/AppcuesNotificationService/**/*.swift'
+  s.exclude_files = 'Sources/AppcuesNotificationService/AppcuesNotificationService.docc'
+end