Add information about math delimiters
Add information about math delimiters

GerHobbelt/MathJax-docs,mathjax/MathJax-docs,mathjax/MathJax-docs,Axure/MathJax-docs,GerHobbelt/MathJax-docs,mitya57/mathjax-docs,Axure/MathJax-docs,mitya57/mathjax-docs