docs: update start-end.md (#8462)

Fixes english and spelling in start-end.md.

components/date-picker/demo/start-end.md

@@ -13,9 +13,9 @@ title:
 
 ## en-US
 
-When `RangePicker` is not satisfied your requirements, try to implement similar functionality with two `DatePicker`.
+When `RangePicker` does not satisfied your requirements, try to implement similar functionality with two `DatePicker`.
 > * Use the `disabledDate` property to limit the start and end dates.
-> * Imporve user experience with `open` `onOpenChange`.
+> * Improve user experience with `open` and `onOpenChange`.
 
 ````jsx
 import { DatePicker } from 'antd';