update readme

Author: ravenq

README.md

@@ -57,6 +57,7 @@ npm install markdown-it-vue
 
 <script>
 import MarkdownItVue from 'markdown-it-vue'
+import 'markdown-it-vue/dist/markdown-it-vue.css'
 export default {
   components: {
     MarkdownItVue

example/components/example.js

@@ -7,7 +7,6 @@ export default `
 
 Note: Only \`h2\` and \`h3\` are shown in toc.
 
-
 ## alter
 
 Markup is similar to fenced code blocks. Valid container types are \`success\`, \`info\`, \`warning\` and \`error\`.