Suggestion to add commands to the dashboard tutorial for clarity

When following the guide to [create a dashboard](https://docs.pepr.dev/v0.32.2/pepr-tutorials/create-pepr-dashboard/), a user will run into an error at step 3 if the kube-prometheus-stack repo isn't added. While it's mentioned on the [repo](https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-prometheus-stack) which is linked on the tutorial page, I might suggest adding it directly to the tutorial for additional clarity, e.g.:

```bash
#Ensure helm repo for kube-prometheus-stack is added
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo update

helm install -f values.yaml monitoring prometheus-community/kube-prometheus-stack
```

Open the create-pepr-dashboard tutorial linked in the issue and inspect step 3, where the kube-prometheus-stack installation is run. Add the stated prometheus-community repository and update commands before the install command. Done means a reader can follow the tutorial without the missing Helm repository error.

Written by the indexing model from the issue text.