docs(input): add demo md clear

src/packages/__VUE/input/doc.en-US.md

@@ -172,6 +172,7 @@ The user can enter content in the text box. Configure the icons on both sides of
       const state = reactive({
         showIcon: '',
         required: '',
+        clear:''
       });
       return {
         state

src/packages/__VUE/input/doc.md

@@ -172,6 +172,7 @@ app.use(Icon);
       const state = reactive({
         showIcon: '',
         required: '',
+        clear:''
       });
       return {
         state