Add doc.

README.md

@@ -20,6 +20,8 @@ static void Main()
 
 - Source Generators
     - [x] Generate C# codes
+    - [ ] Generate properties for implementation types (so that reflections on types can get localized properties which is very important for WPF Bindings)
+    - [ ] Generate localized types for each language item which contains more than one arguments (This fixes different argument orders among different languages.)
 - File formats
     - [x] TOML
     - [x] YAML `🤡 Might be deprecated in the future.`
@@ -32,6 +34,7 @@ static void Main()
     - [ ] Detect (and generate) missing localization keys
     - [ ] Detect (and remove) unused localization keys
     - [ ] Detect arguments mismatch among localized texts (e.g. `Hello, {name:string}` in en but `こんにちは、{errorCode:int}` in ja)
+    - [ ] Detect invalid IETF language tags and report errors
 
 ## Installation
 
@@ -83,3 +86,43 @@ namespace SampleApp;
 [LocalizedConfiguration(Default = "en", Current = "zh-hans")]
 public partial class LocalizedText;
 ```
+
+### 3. Use the generated code
+
+```csharp
+// Program.cs
+static void Main()
+{
+    Console.WriteLine(LocalizedText.Current.App.Title);         // "Hello, World!"
+    Console.WriteLine(LocalizedText.Current.App.Description);   // "This is a sample application."
+    Console.WriteLine(LocalizedText.Current.Cli.Usage);         // "Usage: dotnetCampus.SourceLocalizations [options]"
+    Console.WriteLine(LocalizedText.Current.PressAnyKeyToExit); // "Press any key to exit..."
+}
+```
+
+```xml
+<!-- Avalonia MainWindow.axaml -->
+<TextBlock Text="{Binding App.Title, Source={x:Static l:LocalizedText.Current}}" />
+<TextBlock Text="{Binding App.Description, Source={x:Static l:LocalizedText.Current}}" />
+```
+
+```xml
+<!-- Uno Platform MainPage.xaml -->
+<TextBlock Text="{x:Bind l:Lang.Current.App.Title}" />
+<TextBlock Text="{x:Bind l:Lang.Current.App.Description}" />
+```
+
+```csharp
+// Uno Platform MainPage.xaml.cs
+using dotnetCampus.Localizations;
+
+namespace dotnetCampus.SampleUnoApp;
+
+public sealed partial class MainPage : Page
+{
+    public MainPage() => InitializeComponent();
+
+    // IMPORTANT: The Lang property must be public.
+    public ILocalizedValues Lang => global::dotnetCampus.SampleUnoApp.Localizations.LocalizedText.Current;
+}
+```