Add chat_type and chat_instance fields to WebAppInitData (#14)

src/index.d.ts

@@ -1049,6 +1049,17 @@ export declare namespace TelegramWebApps {
      * Apps launched via the attachment menu.
      */
     readonly chat?: WebAppChat
+    /**
+     * Type of the chat from which the Mini App was opened. Can be either “sender” for a
+     * private chat with the user opening the link, “private”, “group”, “supergroup”, or
+     * “channel”. Returned only for Mini Apps launched from direct links.
+     */
+    readonly chat_type?: 'sender' | 'private' | 'group' | 'supergroup' | 'channel'
+    /**
+     * Global identifier, uniquely corresponding to the chat from which the Mini App was
+     * opened. Returned only for Mini Apps launched from a direct link.
+     */
+    readonly chat_instance?: string
     /**
      * The value of the *startattach* parameter, passed via link. Only returned for Web
      * Apps when launched from the attachment menu via link.