docs(readme): added missing documentation about the newly added customization options

Author: Christian Elies

README.md

@@ -55,6 +55,49 @@ RemoteImage(type: .phAsset(localIdentifier: "541D4013-D51C-463C-AD85-0A1E4EA838F
 })
 ```
 
+## Custom `RemoteImageService`
+
+If you want complete control over the service responsible for managing the state of the view and for fetching the image you could pass an object conforming to the `RemoteImageService` to the related initializer:
+
+```swift
+let url = URL(string: "https://images.unsplash.com/photo-1524419986249-348e8fa6ad4a?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1950&q=80")!
+
+RemoteImage(type: .url(url), service: yourCustomService, errorView: { error in
+    Text(error.localizedDescription)
+}, imageView: { image in
+    image
+    .resizable()
+    .aspectRatio(contentMode: .fit)
+}, loadingView: {
+    Text("Loading ...")
+})
+```
+
+## Custom `RemoteImageURLDataPublisher`
+
+Under the hood by default the `URLSession.shared` is used as the `RemoteImageURLDataPublisher` to fetch the image at the specified URL.
+You can specify a custom publisher through the`remoteImageURLDataPublisher` parameter.
+As an example that's how you could add support for low data mode to the `RemoteImage` view.
+
+```swift
+let url = URL(string: "https://images.unsplash.com/photo-1524419986249-348e8fa6ad4a?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=1950&q=80")!
+
+RemoteImage(type: .url(url), remoteImageURLDataPublisher: {
+    let configuration = URLSessionConfiguration.default
+    // Enable low data mode support
+    configuration.allowsConstrainedNetworkAccess = false
+    return URLSession(configuration: configuration)
+}(), errorView: { error in
+    Text(error.localizedDescription)
+}, imageView: { image in
+    image
+    .resizable()
+    .aspectRatio(contentMode: .fit)
+}, loadingView: {
+    Text("Loading ...")
+})
+```
+
 ## Custom cache
 
 The `RemoteImageService` uses a default cache. To use a custom one just conform to the protocol `RemoteImageCache` and set it on the type `RemoteImageService`.