ADD: Telegram bot as notification provider

README.md

@@ -28,9 +28,11 @@ cp conf/config.example conf/config.json
 
 ### 1. Notification
 
-You want to get notified when _Fredy_ found a new listing. Currently _Fredy_ support Slack to send notification. _Fredy_ also includes a notification adapter to print to the console instead of sending to a services.
+You want to get notified when _Fredy_ found a new listing. Currently _Fredy_ support Slack and Telegram to send notification. _Fredy_ also includes a notification adapter to print to the console instead of sending to a services.
 
-Adding new notification adapter is easy however. See [Contribution](https://github.com/orangecoding/fredy/blob/master/CONTRIBUTION.md) 
+Adding new notification adapter is easy however. See [Contribution](https://github.com/orangecoding/fredy/blob/master/CONTRIBUTION.md)
+
+##### Slack 
 ```json
 "slack": {
   "channel": "someChannel",
@@ -39,6 +41,21 @@ Adding new notification adapter is easy however. See [Contribution](https://gith
 }
 ```
 
+##### Telegram
+```json
+"telegram": {
+  "chatId": "someChannel",
+  "token": "someToken",
+  "enabled": true
+}
+```
+
+For Telegram, you need to create a Bot. This is pretty easy. Open [this](https://telegram.me/BotFather) url on your smartphone and follow the instructions.
+A telegram bot is not allowed to send messages directly to a user, you as a user need to first contact the bot to get a chatId.   
+After the user has send a message to your bot the first time, you can gather the chatId like this: `$ curl -X GET https://api.telegram.org/botYOUR_API_TOKEN/getUpdates`
+
+A more detailed list of instructions can be found here [https://core.telegram.org/bots#botfather](https://core.telegram.org/bots#botfather) 
+
 ### 2. Configure the providers
 
 Configure the providers like described below. To disable a provider just remove its entry from the configuration or set it to `false`.