re-worked README for initial setup

includes all needed steps to get the module working

README.md

@@ -1,10 +1,56 @@
-### Notification by Telegram
+# Notification by Telegram
 Send Icinga 2 notification via Telegram
 
 ![Telegram Notification](img/Telegram.png)
 
-Example Notification Object
+
----------------------------
+## Prepare
+
+### Create your bot
+
+Obviously you need a bot to begin:
+
+Follow the [official Telegram guide](https://core.telegram.org/bots) and do not forget to grab your bot *API TOKEN* (referred to here as *BOTTOKEN*) afterwards
+
+
+### Get your chat_id(s)
+
+You can notify a specific TG user account or throw a message to a TG group.
+
+In order to do so you need to know the corresponding (hidden) ID also called chat_id (-q TELEGRAM_CHATID).
+
+If you want to notify a **group/channel**:
+
+1. add your bot to that group/channel
+1. send with your favorite client a simple mention msg to your bot (e.g. `hi @mybot`)
+1. catch updates for your bot:
+`curl https://api.telegram.org/bot<BOTTOKEN>/getUpdates`
+1. review the output, an example below:
+   > "message":{"message_id":91, "from":{"id":123456789, "is_bot":false,"first_name":"foo","username":"foobar","language_code":"de"}, "chat":{"id":-987654321, "title":"<GROUPNAME>","type":"group","all_members_are_administrators":true},"date":1563547428,"group_chat_created":true}}]}`
+
+    There are 2 important parts here:
+     - a) `"from":{"id":123456789` which is the unique user/chat_id of the user who sends a message to your bot (required to send to a notify to that person directly)
+     - b) `"chat":{"id":-987654321` which is the unique group/channel id of the group where the message has been sent
+
+If you do not want to notify a group i.e. just **a direct user notification**:
+
+1. do the same as above, just at step 1 make a direct message to your bot instead
+1. as you have done a direct message you will only get a "from" id which is all you need here
+
+
+# Examples
+
+### Testing a notification
+
+sending a test notification (replace the token, botname and chat id obviously)
+
+`sudo -u nagios ./service-by-telegram.sh -4 127.0.0.1 -l myhostname -o testingTGnotifiy -p <myBotname> -q <myGroupChatId> -r "<1234134325:blafasel>" -s CRITICAL -c mycomment -b mycommentuser -i https://myicingaserver/icingaweb2 -n maaaaaaaaaaa -d"$(date +%F-%T)" -e serviceshort -u fullservicename -D`
+
+
+### Icinga2 objects
+
+
+#### Example Notification Object
 
 ```ini
 apply Notification "Host by Telegram" to Host {
@@ -19,8 +65,8 @@ apply Notification "Host by Telegram" to Host {
 }
 ```
 
-Command Definitions
+#### Example Command Definitions
--------------------
+
 ```ini
 object NotificationCommand "Notify Host By Telegram" {
     import "plugin-notification-command"
@@ -130,5 +176,6 @@ object NotificationCommand "Notify Service By Telegram" {
     }
 }
 ```
+#### Example Director config
 
 ![Icinga Director Config](img/Telegram_Notification_in_Icinga_Director.jpg)