Fixed description on mathjax page

Author: JianLoong

exampleSite/content/shortcodes/mathjax.en.md

@@ -1,6 +1,7 @@
 ---
 title: "MathJax"
-description: ""
+description: "Display engine for LaTeX, MathML, and AsciiMath 
+notation that works in all modern browsers."
 ---
 
 [Mathjax](https://github.com/mathjax/MathJax) is an open-source JavaScript display engine for LaTeX, MathML, and AsciiMath