improve markdown readme's & and adding ability to send telegram messages to a topic in a supergroup

lib/notification/adapter/telegram.md

@@ -1,12 +1,55 @@
 ### Telegram Adapter
 
-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.
+Use this adapter to send notifications to Telegram via a bot. You will need:
+- A Telegram Bot token (from BotFather)
+- A chat ID (where messages will be sent)
+- Optionally: a thread ID if you want to post into a specific forum topic in a group
 
-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:
+#### Create a bot
+Create a bot with BotFather: open https://telegram.me/BotFather on your phone or in Telegram Desktop and follow the instructions to get your bot token.
 
+#### Getting the chat ID
+A Telegram bot cannot message a user first; you must create a conversation (or add the bot to a group/channel) so Telegram assigns a chat the bot can access.
+
+Steps:
+1. Start a chat with your bot in Telegram (or add the bot to your group/supergroup/channel) and send any message.
+2. Fetch recent updates from the Bot API:
+   ```
+   curl -X GET "https://api.telegram.org/bot{YOUR_TELEGRAM_TOKEN}/getUpdates"
+   ```
+3. In the JSON response, find the message that you just sent and read `message.chat.id`. That value is your `chatId`.
+   - Private chats: `chat.id` is a positive number
+   - Groups/supergroups: `chat.id` is a negative number
+
+Keep your bot token secret. If `getUpdates` returns an empty list, send a new message and try again, or make sure your bot’s privacy settings allow it to see group messages when used in groups.
+
+#### Getting the thread ID (this is optional to be used for forum topics)
+If you want messages to appear inside a specific forum topic of a supergroup with Topics enabled, you also need a thread ID. In the Telegram Bot API this is called `message_thread_id`.
+
+When you need it:
+- Required only for supergroups with Topics enabled when targeting a topic
+- Not used for private chats, basic groups without Topics, or channels
+
+Steps to obtain it:
+1. In your supergroup, enable Topics (Group settings → Manage group → Topics → Enable). Now add a new topic.
+2. Add your created bot to the topic. (Click on the bot and on "Add to group")
+3. Open the desired topic (or create a new one) and send any message inside that topic.
+4. Call `getUpdates` again:
+   ```
+   curl -X GET "https://api.telegram.org/bot{YOUR_TELEGRAM_TOKEN}/getUpdates"
+   ```
+4. In the update for the message you sent inside the topic, read `message.message_thread_id`. That number is your `threadId` for this topic.
+
+Example (truncated):
 ```
-curl -X GET https://api.telegram.org/bot{YOUR_TELEGRAM_TOKEN}/getUpdates
+{
+  "message": {
+    "chat": { "id": -1001234567890, "type": "supergroup" },
+    "message_thread_id": 42,
+    "text": "hello from the topic"
+  }
+}
 ```
+Use `chat.id` as `chatId` and `message_thread_id` as `threadId` in your configuration.
 
-A more detailed list of instructions can be found here [https://core.telegram.org/bots#botfather](https://core.telegram.org/bots#botfather)
+More details about bots and BotFather: https://core.telegram.org/bots#botfather