Docs: Fixes typos and adds enterprise note (#50564)

* Fixes typos and space errors

* Docs: adds note for enterprise users

* Run yarn prettier:write

Co-authored-by: Armand Grillet <armand.grillet@outlook.com>

docs/sources/alerting/migrating-alerts/_index.md

@@ -10,15 +10,17 @@ weight: 101
 
 Grafana Alerting is enabled by default for new installations or existing installations whether or not legacy alerting is configured.
 
+> **Note**: We recommend that Grafana Enterprise customers with more than a dozen Grafana dashboard alert rules do not upgrade and remain on legacy alerting for now by [opting out]({{< relref "opt-out/" >}}). If you do want to upgrade to Grafana Alerting, contact customer support.
+
 Existing installations that do not use legacy alerting will have Grafana Alerting enabled by default unless alerting is disabled in the configuration.
 
-Likewise, existing installations that use legacy alerting will be automatically upgraded to Grafana Alerting unless you have [opted out]({{< relref "opt-out/" >}})of Grafana Alerting before migration takes place. During the upgrade, legacy alerts are migrated to the new alerts type and no alerts or alerting data are lost.
+Likewise, existing installations that use legacy alerting will be automatically upgraded to Grafana Alerting unless you have [opted out]({{< relref "opt-out/" >}}) of Grafana Alerting before migration takes place. During the upgrade, legacy alerts are migrated to the new alerts type and no alerts or alerting data are lost.
 
-Once the upgrade has taken place, you still have the option to roll back [roll back]({{< relref "roll-back/" >}}) to legacy alerting. However, we do not recommend choosing this option. If you do choose to roll back, Grafana will restore your alerts to the alerts you had at the point in time when the upgrade took place. All new alerts and changes made exclusively in Grafana Alerting will be deleted.
+Once the upgrade has taken place, you still have the option to [roll back]({{< relref "roll-back/" >}}) to legacy alerting. However, we do not recommend choosing this option. If you do choose to roll back, Grafana will restore your alerts to the alerts you had at the point in time when the upgrade took place. All new alerts and changes made exclusively in Grafana Alerting will be deleted.
 
 > **Note**: Cloud customers, who do not want to upgrade to Grafana Alerting, should contact customer support.
 
-If you have opted out or rolled back, you can always choose to opt in [opt in]({{< relref "opt-in/" >}}) to Grafana Alerting at a later point in time.
+If you have opted out or rolled back, you can always choose to [opt in]({{< relref "opt-in/" >}}) to Grafana Alerting at a later point in time.
 
 The following table provides details on the upgrade for Cloud, Enterprise, and OSS installations and the new Grafana Alerting UI.