A markdown file generally has a .md or a .markdown extension. It uses plain text formatting syntax, which is pretty easy to learn. For example, bulleted lists are denoted with an asterix before each line item and subheadings with one or more hash marks.

This markdown cheatsheet is handy to learn how to do things. https://enterprise.github.com/downloads/en/markdown-cheatsheet.pdf

Try editing the cv.md file with your info (remember to click the edit pencil button). When you're done, click the green "Commit changes" button at the bottom to save your changes.

Reload your website to make sure that the changes worked. It sometimes takes a little time for GitHub to update the files, so be patient if they don't appear immediately.

A full tutorial about writing markdown can be found here: The Magic of Markdown by Ted Laderas

Markdown is a lightweight way to format text that is much easier to manipulate than working with HTML files directly.

GitHub has a "translation engine" that will transform and format your Markdown files for the website, making them browser friendly.

This means you can concentrate on making content rather than every little site detail.