[TF-28096] Clarify events that team notifications can subscribe to (#866)

Team notifications can only subscribe to change requests, and have never
had run progress or other events available as options for subscription.
Clarifying the docs here to avoid confusion in the future, the team will
update the docs when this feature supports other event types in the
future.

[JIRA](https://hashicorp.atlassian.net/browse/TF-28096)

Author: nylkotuby

content/terraform-docs-common/docs/cloud-docs/users-teams-organizations/teams/notifications.mdx

@@ -5,7 +5,7 @@ description: Learn how to set up team notifications to notify team members on ex
 
 # Manage team notifications
 
-HCP Terraform can use webhooks to notify external systems about run progress, change requests, and other events. Team notifications allow you to configure relevant alerts that notify teams you specify whenever a certain event occurs. 
+HCP Terraform can use webhooks to notify external systems about events. Team notifications allow you to configure relevant alerts that notify teams you specify whenever a certain event occurs. You can only configure team notifications to notify your team of [change requests](/terraform/cloud-docs/workspaces/change-requests).
 
 @include 'tfc-package-callouts/notifications.mdx'
 
@@ -125,4 +125,4 @@ You can use some of the values in the payload to retrieve additional information
 
 Slack notifications use Slack's own protocols to verify HCP Terraform's webhook requests.
 
-Generic notifications can include a signature to verify the request. For notification configurations that include a secret token, HCP Terraform's webhook requests include an `X-TFE-Notification-Signature` header containing an HMAC signature computed from the token using the SHA-512 digest algorithm. The notification’s receiving service is responsible for validating the signature. For more information and an example of how to validate the signature, refer to the [API documentation](/terraform/cloud-docs/api-docs/notification-configurations#notification-payload).
+Generic notifications can include a signature to verify the request. For notification configurations that include a secret token, HCP Terraform's webhook requests include an `X-TFE-Notification-Signature` header containing an HMAC signature computed from the token using the SHA-512 digest algorithm. The notification’s receiving service is responsible for validating the signature. For more information and an example of how to validate the signature, refer to the [API documentation](/terraform/cloud-docs/api-docs/notification-configurations#notification-payload).

content/terraform-enterprise/1.0.x/docs/enterprise/users-teams-organizations/teams/notifications.mdx

@@ -8,7 +8,7 @@ source: terraform-docs-common
 
 # Manage team notifications
 
-HCP Terraform can use webhooks to notify external systems about run progress, change requests, and other events. Team notifications allow you to configure relevant alerts that notify teams you specify whenever a certain event occurs. 
+HCP Terraform can use webhooks to notify external systems about events. Team notifications allow you to configure relevant alerts that notify teams you specify whenever a certain event occurs. You can only configure team notifications to notify your team of [change requests](/terraform/enterprise/workspaces/change-requests).
 
 @include 'tfc-package-callouts/notifications.mdx'