update readme

README.md

@@ -11,10 +11,11 @@ We recommend using [The Things Network](https://www.thethingsnetwork.org/) (TTN)
     - [Database](#database)
     - [Configuration](#configuration)
 2. [TTN Integration](#ttn-integration)
-3. [Add a Location Tracker](#add-a-location-tracker)
+3. [Prometheus Metrics](#prometheus-metrics)
+4. [Add a Location Tracker](#add-a-location-tracker)
     - [Onboard SenseCAP T1000-B](#onboard-sensecap-t1000-b)
     - [Register SenseCAP T1000-B](#register-sensecap-t1000-b)
-4. [Testing](#testing)
+5. [Testing](#testing)
     - [Testing Webhook](#testing-webhook)
     - [Emulating Wigle API](#emulating-wigle-api)
 
@@ -49,6 +50,9 @@ Add a addidtional header:
 - Type: `authorization` 
 - Value: `Bearer your-very-secure-token-from-the-env-file`
 
+### Prometheus Metrics
+Use `https://your.domain.tld/api/metrics` to retrieve useful insides for monitoring.
+
 ## Add a Location Tracker
 We use the [SenseCAP T1000-B](https://www.seeedstudio.com/SenseCAP-Card-Tracker-T1000-B-p-5698.html) from seeedstudio because of the fair price and multiple location providers. However, you can use any LoRaWAN-enabled tracker that is compatible with TTN and supports the required payload fields.