docs: add documentation for notifications feature (#14478)

codersdk/deployment.go

@@ -2419,9 +2419,9 @@ Write out the current server config as YAML to stdout.`,
 			Description: "Password to use with PLAIN/LOGIN authentication.",
 			Flag:        "notifications-email-auth-password",
 			Env:         "CODER_NOTIFICATIONS_EMAIL_AUTH_PASSWORD",
+			Annotations: serpent.Annotations{}.Mark(annotationSecretKey, "true"),
 			Value:       &c.Notifications.SMTP.Auth.Password,
 			Group:       &deploymentGroupNotificationsEmailAuth,
-			YAML:        "password",
 		},
 		{
 			Name:        "Notifications: Email Auth: Password File",

codersdk/deployment_test.go

@@ -14,9 +14,10 @@ import (
 	"github.com/stretchr/testify/require"
 	"gopkg.in/yaml.v3"
 
+	"github.com/coder/serpent"
+
 	"github.com/coder/coder/v2/coderd/util/ptr"
 	"github.com/coder/coder/v2/codersdk"
-	"github.com/coder/serpent"
 )
 
 type exclusion struct {
@@ -77,6 +78,9 @@ func TestDeploymentValues_HighlyConfigurable(t *testing.T) {
 		"Provisioner Daemon Pre-shared Key (PSK)": {
 			yaml: true,
 		},
+		"Notifications: Email Auth: Password": {
+			yaml: true,
+		},
 	}
 
 	set := (&codersdk.DeploymentValues{}).Options()