Instant reply to API on incoming webhook request

[jacklul]

Basically webhook can output a json containing a request like sendmessage and when Telegram API enters it it will instantly execute that call.

This can be particularly useful if the bot always replies with on request to the API, instead of doing request to the API it will be served when script finishes.

To think through:

• Botan will put delay on this
• A way to cleanly implement this