update readme with getting updates instructions

README.md

@@ -27,3 +27,34 @@ executor.execute(GetMe())
 As a result you will receive `User` object. This object used as is now (as in API documentation), but it is possible
 that this class will be renamed to `RawUser` and you will be able to get real realisation of this object like `Bot` (in
 cases when `isBot` == `true`) or `User` (otherwise)
+
+## Getting updates
+
+In this library currently realised two ways to get updates from telegram:
+
+* Polling - in this case bot will request updates from time to time (you can set up delay between requests)
+* Webhook via reverse proxy or something like this
+
+### Updates filters
+
+Currently webhook method contains `UpdatesFilter` as necessary argument for getting updates.
+`UpdatesFilter` will sort updates and throw their into different callbacks. Currently supporting
+separate getting updates for media groups - they are accumulating with debounce in one second
+(for being sure that all objects of media group was received).
+
+Updates polling also support `UpdatesFilter` but you must not use it and can get updates directly
+in `UpdateReceiver`, which you will provide to `startGettingOfUpdates` method
+
+### Webhook set up
+
+If you wish to use webhook method, you will need:
+
+* White IP - your IP address or host, which available for calling. [TelegramBotAPI](https://core.telegram.org/bots/api#setwebhook)
+recommend to use some unique address for each bot which you are using
+* SSL certificate. You can obtain address using your provider, [Let'sEncrypt](https://letsencrypt.org/) or [create it](https://core.telegram.org/bots/self-signed)
+* Nginx or something like this
+
+Template for Nginx server config you can find in [this gist](https://gist.github.com/InsanusMokrassar/fcc6e09cebd07e46e8f0fdec234750c4#file-nginxssl-conf)
+
+For webhook you must provide `File` with public part of certificate, `URL` where bot placed and inner `PORT` which
+will be used to start receiving of updates.