Update grafana to matrix alerting docs

documentation/grafana.markdown

@@ -68,7 +68,59 @@ or on the left side via `Dashboards` > `Snapshots`. The same can be done with si
 
 ## Sending alerts to Matrix
 
-Follow the instructions to use the [[webhook bridge|/chat/matrix/bridges/#webhooks-slack-compatible]].
+| Key Terms           | Description                                       |
+|---------------------|---------------------------------------------------|
+| Alert rule          | Define the conditions that trigger an alert       |
+| Alert instance      | Specific occurrence of an alert                   |
+| Contact point       | Destination where alert notifications are sent    |
+| Notification policy | Determine how alerts are routed to contact points |
+
+### 1. Set up alert rule
+
+[/alerting/list](https://grafana.phys.ethz.ch/alerting/list)
+
+Provide the following settings:
+
+- Select data source
+- Define condition for firing
+- Evaluation Behavior
+  - Select Grafana folder
+  - Evaluation Group
+  - Pending Period
+
+### 2. Set up contact point
+
+Follow the instructions to use the [[Webhook API|https://readme.phys.ethz.ch/chat/matrix/bridges/#webhook-api-grafana-slack]] with the Grafana `webhook` integration: see [[Grafana webhook notification|https://readme.phys.ethz.ch/chat/matrix/bridges/#grafana-webhook-notification]].
+
+[/alerting/notifications](https://grafana.phys.ethz.ch/alerting/notifications)
+
+| Field       | Setting                |
+| ----------- | -----------------------|
+| Integration | Webhook                |
+| URL         | URL to the webhook API |
+
+- You can send a test message to verify that everything works
+- Optional: add `?template=<template>` to specify how notifications get displayed.
+  See [docs](https://gitlab.ethz.ch/isgphys/webhook-to-matrix-hookshot#configuration).
+
+### 3. Define notifcation policy
+
+[/alerting/routes](https://grafana.phys.ethz.ch/alerting/routes)
+
+> A notification policy connects alert rules to contact point
+
+| Field           | Settings                                      |
+|-----------------|-----------------------------------------------|
+| Matching labels | Labels that uniquely identify your alert rule |
+| Contact point   | Select your contact point                     |
+
+### Grafana Alerting docs
+
+- [Alerting](https://grafana.com/docs/grafana/latest/alerting/)
+- [Alert Rules](https://grafana.com/docs/grafana/latest/alerting/fundamentals/alert-rules/)
+- [State and health of alert rules](https://grafana.com/docs/grafana/latest/alerting/fundamentals/alert-rules/state-and-health/)
+- [Labels and Annotations](https://grafana.com/docs/grafana/latest/alerting/fundamentals/alert-rules/annotation-label/)
+
 
 ## Service overview