update toast placement options (#7615)

Author: reidbarber

packages/@react-spectrum/toast/docs/Toast.mdx

@@ -167,7 +167,7 @@ function Example() {
 
 ## Placement
 
-By default, toasts are displayed at the bottom center of the screen. This can be changed by setting the `placement` prop on the `ToastContainer` to `'top start'`, `'top'`, `'top end'`, `'bottom start'`, `'bottom'`, or `'bottom end'`.
+By default, toasts are displayed at the bottom center of the screen. This can be changed by setting the `placement` prop on the `ToastContainer` to `'top'`, `'top end'`, `'bottom'`, or `'bottom end'`.
 
 ```tsx example render=false hidden
 <ToastContainer placement="bottom end" />

packages/@react-spectrum/toast/src/ToastContainer.tsx

@@ -21,7 +21,7 @@ import {Toaster} from './Toaster';
 import {ToastOptions, ToastQueue, useToastQueue} from '@react-stately/toast';
 import {useSyncExternalStore} from 'use-sync-external-store/shim/index.js';
 
-export type ToastPlacement = 'top start' | 'top' | 'top end' | 'bottom start' | 'bottom' | 'bottom end';
+export type ToastPlacement = 'top' | 'top end' | 'bottom' | 'bottom end';
 
 export interface SpectrumToastContainerProps extends AriaToastRegionProps {
   placement?: ToastPlacement

packages/@react-spectrum/toast/stories/Toast.stories.tsx

@@ -46,7 +46,7 @@ export default {
     },
     placement: {
       control: 'select',
-      options: [undefined, 'top start', 'top', 'top end', 'bottom start', 'bottom', 'bottom end']
+      options: [undefined, 'top', 'top end', 'bottom', 'bottom end']
     }
   }
 };