feat(notification)!: ToastNotification props

Add new props: statusIconDescription and closeButtonDescription

BREAKING CHANGE: remove iconDescription prop

docs/src/pages/components/InlineNotification.svx

@@ -7,6 +7,10 @@ components: ["InlineNotification", "NotificationActionButton"]
   import Preview from "../../components/Preview.svelte";
 </script>
 
+Notification that appears inline.
+
+See also: [ToastNotification](ToastNotification)
+
 ## Default (error)
 
 <InlineNotification title="Error:" subtitle="An internal server error occurred." />

docs/src/pages/components/ToastNotification.svx

@@ -3,6 +3,13 @@
   import Preview from "../../components/Preview.svelte";
 </script>
 
+Toasts are non-modal, time-based window elements used to display short messages;
+they usually appear at the top of the screen and disappear after a few seconds.
+
+See [detailed
+usage](https://carbondesignsystem.com/components/notification/usage).  
+See also: [InlineNotification](InlineNotification)
+
 ## Default (error)
 
 <ToastNotification title="Error" subtitle="An internal server error occurred." caption="{new Date().toLocaleString()}" />
@@ -30,6 +37,19 @@ Set `fullWidth` to `true` for the notification to span the full width of its con
   <strong slot="caption">{new Date().toLocaleString()}</strong>
 </ToastNotification>
 
+## Accessible icon descriptions
+
+The status icon and close button icon descriptions appear on cursor hover and are read
+by assistive technology. Default descriptions are provided in English and can be
+overridden via `statusIconDescription` and `closeButtonDescription`.
+
+<ToastNotification 
+  title="错误"
+  subtitle="发生内部服务器错误"
+  statusIconDescription="错误图标"
+  closeButtonDescription="关闭通知"
+/>
+
 ## Hidden close button
 
 <ToastNotification hideCloseButton kind="warning" title="Scheduled maintenance" subtitle="Maintenance will last 2-4 hours." caption="{new Date().toLocaleString()}" />