Docs for alerts on project errors (#5529)

* Docs for alerts on project errors

* Cleanup and some minor edits

Updated the overview, added a few cross-reference links to the docs, and made some minor cleanup

---------

Co-authored-by: Andrew Tsao <[email protected]>

docs/docs/deploy/project-errors.md

@@ -0,0 +1,84 @@
+---
+title: Managing Project Errors
+description: Explore and configure alerts for project errors
+sidebar_label: Managing Project Errors
+sidebar_position: 25
+---
+
+## Overview
+
+Rill projects can go into an error state for many reasons, such as a malformed YAML file, missing credentials for a connector, or a breaking change in a data type.
+Regardless of the error, Rill Cloud takes various steps to surface, manage, and contain errors:
+
+- **Visibility:** Admins will always be able to view the project status at the individual resource level within Rill Cloud using the `Status` tab or by using the [rill project status](/reference/cli/project/status.md) CLI command.
+- **Isolation:** Rill Cloud will handle errors at the individual resource level. For example, if a dashboard falls into an error state or fails to reconcile, all other dashboards should remain available. 
+- **Fallback:** Rill Cloud will attempt to fall back to the most recent valid state when possible. For example, if the underlying model for a dashboard fails to build, the dashboard will keep serving from the most recent valid state.
+
+## Receive alerts for project errors
+
+To help you quickly identify and fix errors, you can configure a Rill alert that will trigger when one or more resources in your project enter an error state. The alert must be configured using a YAML file committed to your Rill project repository (configuration through the UI is not yet possible).
+
+:::tip Want to learn more about alerts?
+
+Besides alerting on project errors, it is possible to configure generic alerts in your dashboards based on specific thresholds or conditions being met. For more details, check our our [alerts documentation](/explore/alerts/alerts.md)!
+
+:::
+
+### Configure an email alert
+
+To configure an email alert for project errors, add a file named `project_errors.yaml` to your Rill project with the contents below. Remember to update the `recipients` field to your desired alert recipients.
+
+```yaml
+type: alert
+
+# Check the alert every 10 minutes.
+refresh:
+  cron: "*/10 * * * *"
+
+# Query for all resources with a reconcile error.
+# The alert will trigger when the query result is not empty.
+data:
+  resource_status:
+    where_error: true
+
+# Send notifications by email
+notify:
+  email:
+    recipients: [[email protected]]
+```
+
+:::info Don't forget to commit your changes!
+
+After making these changes, you should commit and [push these changes](/deploy/existing-project/github-101.md#pushing-changes) to your git repository.
+
+:::
+
+### Configure a Slack alert
+
+To configure a Slack alert for project errors, first follow the Slack configuration steps described on [Configuring Slack integration](../explore/alerts/slack.md). Next, add a file named `project_errors.yaml` to your Rill project with the contents below. Remember to update the `channels` field to your desired destination channel.
+
+```yaml
+type: alert
+
+# Check the alert every 10 minutes.
+refresh:
+  cron: "*/10 * * * *"
+
+# Query for all resources with a reconcile error.
+# The alert will trigger when the query result is not empty.
+data:
+  resource_status:
+    where_error: true
+
+# Send notifications in Slack.
+# Follow these steps to configure a Slack token: https://docs.rilldata.com/explore/alerts/slack.
+notify:
+  slack:
+    channels: [rill-alerts]
+```
+
+:::info Don't forget to commit your changes!
+
+After making these changes, you should commit and [push these changes](/deploy/existing-project/github-101.md#pushing-changes) to your git repository.
+
+:::