Telegram Notification Template monitorJSON not populated

**Describe the bug**

The `monitorJSON` variable doesn't seem to be populated when using the Telegram notifier:

The template:
```
🔔 Peekaping Notification

Message:
{{ msg }}

Raw Data:
{{ monitorJSON }}
```

The notification content:
```
🔔 Peekaping Notification

Message:
Get "https://xxx.abc.de": tls: failed to verify certificate: x509: certificate is valid for ingress.local, not ...

Raw Data:

```

Without this data these notifications are pretty much useless, since recovery looks like this by default:

**Database**
- postgresql

**Expected behavior**
Some data in the variable, and preferably some examples on how to use it.

**Screenshots**

Look for the Telegram notifier implementation, likely in a `notifier` or `notification` package. Find where the template variables like `monitorJSON` are populated. The bug is that this variable is empty; trace the data flow from the monitor object to the template rendering. Check existing tests for notifiers to understand the expected structure.

索引モデルが issue の本文から書いたものです。