chore: fix front matter broken (#2390)

Co-authored-by: Luffy <52o@qq52o.cn>

Author: LBZZYZ

docs/_media/example-with-yaml.md

@@ -3,4 +3,4 @@ author: John Smith
 date: 2020-1-1
 ---
 
-> This is from the `example.md`
+> This is from the `example-with-yaml.md`

docs/embed-files.md

@@ -44,6 +44,8 @@ You will get:
 
 ## Markdown with YAML Front Matter
 
+Front Matter, commonly utilized in blogging systems like Jekyll, serves to define metadata for a document. The [front-matter.js](https://www.npmjs.com/package/front-matter) package facilitates the extraction of metadata (front matter) from documents.
+
 When using Markdown, YAML front matter will be stripped from the rendered content. The attributes cannot be used in this case.
 
 ```markdown

docs/index.html

@@ -219,6 +219,7 @@
     </script>
     <script src="//cdn.jsdelivr.net/npm/docsify@4/lib/docsify.min.js"></script>
     <script src="//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/search.min.js"></script>
+    <script src="//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/front-matter.min.js"></script>
     <script src="//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/ga.min.js"></script>
     <script src="//cdn.jsdelivr.net/npm/docsify@4/lib/plugins/matomo.min.js"></script>
     <script src="//cdn.jsdelivr.net/npm/prismjs@1/components/prism-bash.min.js"></script>