refactor: standardized files name (#1884)

style-guide: https://panjiachen.github.io/vue-element-admin-site/guide/advanced/style-guide.html#style-guide

src/views/components-demo/drag-dialog.vue

@@ -17,7 +17,7 @@
 </template>
 
 <script>
-import elDragDialog from '@/directive/el-dragDialog' // base on element-ui
+import elDragDialog from '@/directive/el-drag-dialog' // base on element-ui
 
 export default {
   name: 'DragDialogDemo',

src/views/components-demo/mixin.vue

@@ -115,7 +115,7 @@
 import PanThumb from '@/components/PanThumb'
 import MdInput from '@/components/MDinput'
 import Mallki from '@/components/TextHoverEffect/Mallki'
-import DropdownMenu from '@/components/Share/dropdownMenu'
+import DropdownMenu from '@/components/Share/DropdownMenu'
 import waves from '@/directive/waves/index.js' // 水波纹指令
 
 export default {