feat: add support for autocomplete interactions (#6672)

Co-authored-by: Suneet Tipirneni <suneettipirneni@icloud.com>

src/structures/Interaction.js

@@ -160,6 +160,14 @@ class Interaction extends Base {
     return InteractionTypes[this.type] === InteractionTypes.APPLICATION_COMMAND && typeof this.targetId !== 'undefined';
   }
 
+  /**
+   * Indicates whether this interaction is an {@link AutocompleteInteraction}
+   * @returns {boolean}
+   */
+  isAutocomplete() {
+    return InteractionTypes[this.type] === InteractionTypes.APPLICATION_COMMAND_AUTOCOMPLETE;
+  }
+
   /**
    * Indicates whether this interaction is a {@link MessageComponentInteraction}.
    * @returns {boolean}