Doing a set of suggestions here following our call - cc @amsoedal! I've just merged up latest, will do a test run here but wanted to get changes to make it a bit more extensible for other clouds and easier to consume in front of your eyes. Philo added some color around the purposes for the public events (makes sense!), so was trying to make using them a bit cleaner on the client side, e.g.:
```cs
if (evt is AzureMaintenanceEvent ame && ame.NotificationType == AzureMaintenanceEvent.NotificationTypes.NodeMaintenanceStarting)
```

The extensibility model would be other cloud providers adding a PR here, which would consist in total of their handler (if different) and adding to the base `ServerMaintenanceEvent` (not meant to be externally extensible at the moment).

Can you please provide thoughts?

Co-authored-by: Michelle Soedal <ansoedal@microsoft.com>