Mention "callback_query" in README

Notes:

  Merge branch 'patch-1' of https://github.com/koloboid/node-telegram-bot-api into pr/163

References:

  * PR #163: https://github.com/yagop/node-telegram-bot-api/pull/163

README.md

@@ -33,7 +33,7 @@ There are some other examples on [examples](https://github.com/yagop/node-telegr
 
 ### Events
 Every time TelegramBot receives a message, it emits a `message`. Depending on which  [message](https://core.telegram.org/bots/api#message) was received, emits an event from this ones: `text`, `audio`, `document`, `photo`, `sticker`, `video`, `voice`, `contact`, `location`, `new_chat_participant`, `left_chat_participant`, `new_chat_title`, `new_chat_photo`, `delete_chat_photo`, `group_chat_created`. Its much better to listen a specific event rather than a `message` in order to stay safe from the content.
-TelegramBot emits `inline_query` when receives an [Inline Query](https://core.telegram.org/bots/api#inlinequery) and `chosen_inline_result` when receives a [ChosenInlineResult](https://core.telegram.org/bots/api#choseninlineresult). Bot must be enabled on [inline mode](https://core.telegram.org/bots/api#inline-mode)
+TelegramBot emits `inline_query` when receives an [Inline Query](https://core.telegram.org/bots/api#inlinequery) and `chosen_inline_result` when receives a [ChosenInlineResult](https://core.telegram.org/bots/api#choseninlineresult). Also, `callback_query` event fires when a `callback_query` update received from Telegram (https://core.telegram.org/bots/api#update). Bot must be enabled on [inline mode](https://core.telegram.org/bots/api#inline-mode)
 * * *
 
 ### WebHooks