refactor example demo (#713)

* refactor: Adjust the example directory structure

* perf form demo

* refine editor-slide-upload css

* refine demo

src/views/example/create.vue

@@ -0,0 +1,13 @@
+<template>
+  <article-detail :is-edit='false'></article-detail>
+</template>
+
+<script>
+import ArticleDetail from './components/ArticleDetail'
+
+export default {
+  name: 'createForm',
+  components: { ArticleDetail }
+}
+</script>
+