create a markdown 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: learning markdonw

# This is an <h1> tag
## This is an <h2> tag
###### This is an <h6> tag