update: update the comments.

Author: Koooooo-7

src/plugins/search/markdown-to-txt.js

@@ -1,6 +1,6 @@
 /**
- * This is a modified version of the
- * [markdown-to-txt](https://www.npmjs.com/package/markdown-to-txt) library.
+ * This is a modified version of the [markdown-to-txt](https://www.npmjs.com/package/markdown-to-txt) library.
+ * The original source code can be found at [markdown-to-txt](https://github.com/ejrbuss/markdown-to-txt).
  */
 import { marked } from 'marked';
 import { escape, unescape } from 'lodash';