Markdown file extension is md. Or run the command Clip MarkdownMath to HTML to copy the corresponding HTML source to the underlying systems clipboard. You can easily reference and equation like 1 1 with the standard eqref label syntax note - no delimiters.
Latex to render mathematical and scientific writing.
To write the equations. Press escape key to go to command mode. Since I am writing blog post that hosted by Github with Editor Atom and use plugin markdown-preview-plus and mathjax-wrapper and use mathjax Javascript display the math symbols on the web page. To write the equations.