doc(wrappers/ios): add basic usage section in iOS readme

Author: benjohnde

wrappers/ios/README.md

@@ -1,3 +1,27 @@
 # ZXingCpp iOS Framework
 
-Add the iOS wrapper either as a local Swift Package by adding it as a dependency to your app or add the repository, the Package.swift file is automatically picked.
+## Usage
+
+For general usage, please compare the source code provided in the demo project.
+
+### Swift PM
+
+As this repository provides a `Package.swift` on root level, you can add `zxing-cpp` including wrapper code by adding a Package Dependency in Xcode.
+
+An alternative way is to check this repository out and add it as a local Swift Package by adding it as dependency to your app.
+
+### CocoaPods
+
+As an alternative way, you can also rely on [CocoaPods](https://cocoapods.org/pods/zxing-cpp). Just add the Pod as dependency, for instance:
+
+```
+pod 'zxing-cpp'
+```
+
+If you just need the core without the wrapper code, you can also rely on:
+
+```
+pod 'zxing-cpp/Core'
+```
+
+The module to be imported is named `ZXingCpp`.

zxing-cpp.podspec

@@ -4,6 +4,7 @@ Pod::Spec.new do |s|
   s.summary = 'C++ port of ZXing'
   s.homepage = 'https://github.com/zxing-cpp/zxing-cpp'
   s.author = 'axxel'
+  s.readme = 'https://raw.githubusercontent.com/zxing-cpp/zxing-cpp/master/wrappers/ios/README.md'
   s.license = {
     :type => 'Apache License 2.0',
     :file => 'LICENSE'