show image in github readme code example

Example 1: image in github readme

![Alt text](relative/path/to/img.jpg?raw=true "Title")

Example 2: github readme.md add image

![GitHub Logo](/images/logo.png)
Format: ![Alt Text](url)

Example 3: how to add image in github readme

![alt text](http://url/to/img.png)

Example 4: how to add image in readme.md

![alt text](https://github.com/[username]/[reponame]/blob/[branch]/image.jpg?raw=true)