Use a markdown-it-katex fork with latest KaTeX support

Signed-off-by: Yousef Sultan <[email protected]>

Author: Yousef Sultan

README.md

@@ -29,7 +29,7 @@ Supported Markdown Syntax:
 
 `*SyntaxHighlighter` work with [Prism](https://prismjs.com) recommend
 
-`*katex` need add [katex css](https://unpkg.com/katex/dist/katex.min.css).
+`*katex` need add [katex css](https://cdn.jsdelivr.net/npm/katex@0.11.1/dist/katex.min.css).
 
 # Example