what is a markdown file code example

Example 1: what is a markdown .md file

A file with the .MD or .MARKDOWN file extension might be a Markdown Documentation file. It's a plain text file that uses the Markdown language to describe how to convert a text document to HTML. README.md is a common MD file that holds text instructions.

Example 2: markdown

Markdown is a lightweight markup language with plain-text-formatting syntax,
created in 2004 by John Gruber and Aaron Swartz.
Markdown is often used for formatting readme files,
for writing messages in online discussion forums, 
and to create rich text using a plain text editor.