is a markup language with plain text formatting syntax designed so that it can be converted to HTML and many other formats using a tool by the same name. Markdown is often used to format readme files, for writing messages in online discussion forums, and to create rich text using a plain text editor.
Markdown is a lightweight and easy-to-use syntax for styling all forms of writing on the GitHub platform.
Markdown Basics allows you to write using an easy-to-read, easy-to-write plain text format, which then converts to valid HTML for viewing on GitHub.
You can also read Mastering Markdown for 3 minute read from here.
If you’re using Macintosh, another easy way to edit and view Markdown text formatting syntax is to use ideally LightPaper for Mac.
LightPaper – is a simple, beautiful, powerful, yet free text editor for passionate writers. You can use LightPaper to write any kind of text documents — blogs, articles, notes, READMEs, TODOs, or the next chapter of your new novel. Its simple interface gets out of your way, allowing you to focus on writing. To remove distractions, you can switch to Distraction-Free Mode to completely immerse yourself in your current paragraph. It comes bundled with a handful of themes and beautiful fonts. You can also easily create your own themes or add existing ones.