fix: Issue 374 notice-wrapper::after Style in stack-expanded (#375)

Author: ilya-vol

assets/index.less

@@ -239,7 +239,7 @@
             pointer-events: auto;
           }
 
-          &::after {
+          &::before {
             content: "";
             position: absolute;
             left: 0;

docs/examples/stack.tsx

@@ -15,7 +15,7 @@ const getConfig = () => ({
 });
 
 const Demo = () => {
-  const [{ open }, holder] = useNotification({ motion, stack: true });
+  const [{ open }, holder] = useNotification({ motion, stack: true, closable: true });
 
   return (
     <Context.Provider value={{ name: 'bamboo' }}>