Added example to `autocompletion`

docs/guides/int_framework/autocompletion.md

@@ -18,6 +18,8 @@ AutocompleteHandlers raise the `AutocompleteHandlerExecuted` event on execution.
 
 A valid AutocompleteHandlers must inherit [AutocompleteHandler] base type and implement all of its abstract methods.
 
+[!code-csharp[Autocomplete Command Example](samples/autocompletion/autocomplete-example.cs)]
+
 ### GenerateSuggestionsAsync()
 
 The Interactions Service uses this method to generate a response of an Autocomplete Interaction.

docs/guides/int_framework/samples/autocompletion/autocomplete-example.cs

@@ -0,0 +1,20 @@
+// you need to add `Autocomplete` attribute before parameter to add autocompletion to it
+[SlashCommand("command_name", "command_description")]
+public async Task ExampleCommand([Summary("parameter_name"), Autocomplete(typeof(ExampleAutocompleteHandler))] string parameterWithAutocompletion)
+    => await RespondAsync($"Your choice: {parameterWithAutocompletion}");
+
+public class ExampleAutocompleteHandler : AutocompleteHandler
+{
+    public override async Task<AutocompletionResult> GenerateSuggestionsAsync(IInteractionContext context, IAutocompleteInteraction autocompleteInteraction, IParameterInfo parameter, IServiceProvider services)
+    {
+        // Create a collection with suggestions for autocomplete
+        IEnumerable<AutocompleteResult> results = new[]
+        {
+            new AutocompleteResult("Name1", "value111"),
+            new AutocompleteResult("Name2", "value2")
+        };
+
+        // max - 25 suggestions at a time
+        return AutocompletionResult.FromSuccess(results.Take(25));
+    }
+}