README update

Author: Evgenas

README.md

@@ -49,4 +49,78 @@ gamma_errors:
     telegram_channel:
         auth_key: '%env(GAMMA_ERRORS_TELEGRAM_AUTH_KEY)%'
         chat_id: "%env(GAMMA_ERRORS_TELEGRAM_CHAT_ID)%"
-````
+````
+
+## 3. Creating a bot
+
+Start a conversation with @BotFather.
+
+````
+You: /newbot
+>>>>>>>>>>
+@BotFather: Alright, a new bot. How are we going to call it? Please choose a name for your bot.
+<<<<<<<<<<
+You: Sample Error Bot
+>>>>>>>>>>
+@BotFather: Good. Now let's choose a username for your bot. It must end in `bot`. Like this, for example: 
+TetrisBot or tetris_bot.
+<<<<<<<<<<
+Me: test_error_bot
+>>>>>>>>>>
+@BotFather: Done! Congratulations on your new bot. You will find it at telegram.me/cronus_bot. You can now add a 
+description, about section and profile picture for your bot, see /help for a list of commands. By the way, when 
+you've finished creating your cool bot, ping our Bot Support if you want a better username for it. Just make sure 
+the bot is fully operational before you do this.
+
+Use this token to access the HTTP API:
+111111:xxxx-xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+
+For a description of the Bot API, see this page: https://core.telegram.org/bots/api
+````
+
+## 4. Get chat identifier
+
+After the created bot was added to your project's group you should retrieve its chat_id 
+
+Make POST request to URL: https://api.telegram.org/bot_token_/getUpdates
+
+Example:
+
+Request
+
+````
+curl -X POST https://api.telegram.org/bot111111:xxxx-xxxxxxxxxxxxxxxxxxxxxxxxxxxxx/getUpdates
+````
+
+Response
+
+````
+{
+"ok": true,
+"result": [
+  {
+    "update_id": 222222,
+    "message": {
+      "message_id": 3333,
+      "from": {
+        "id": 444444,
+        "first_name": "Test",
+        "last_name": "Test",
+        "username": "test"
+      },
+      "chat": {
+        "id": -111111
+        "first_name": "Test",
+        "last_name": "Test",
+        "username": "test",
+        "type": "private"
+      },
+      "date": 1480701504,
+      "text": "test"
+    }
+  }
+]
+}
+````
+
+chat_id is the number "-111111".