Add step on starting prom

Author: Bibas

pages/cockpit/how-to/federate-scaleway-metrics.mdx

@@ -19,7 +19,7 @@ In this page, we will show you how to federate your Scaleway metrics using the `
 
  - A Scaleway account logged into the [console](https://console.scaleway.com)
  - [Owner](/iam/concepts/#owner) status or [IAM permissions](/iam/concepts/#permission) allowing you to perform actions in the intended Organization
- - [Created](/cockpit/how-to/create-token/) a Cockpit token with read access in the same region as the metrics data source
+ - [Created](/cockpit/how-to/create-token/) a Cockpit token that have query metrics priviledge in the same region as the metrics data source
  - A running [Prometheus](https://prometheus.io) instance
 
 <Message type="info">
@@ -83,8 +83,8 @@ Once you have configured your `prometheus.yml` file, you can use docker-compose
     command:
       - '--config.file=/etc/prometheus/prometheus.yml'
     ```
-
-2. Go to `http://localhost:9090/targets` and you should see your newly created target, federating your Scaleway metrics.
+2. Run `docker-compose up -d` to start your Prometheus instance
+3. Go to `http://localhost:9090/targets` and you should see your newly created target, federating your Scaleway metrics.
 
 ## Monitor your federation volumes