Remove Codu logo from pull request template

[John-Paul-Larkin]

Context

The pull request template contains a markdown link to the Codu image.
This image is superfluous and can be removed.

Note : This one should be left for beginners.

Expected Behavior

This is the offending line of code. Please remove it.
Codu Logo](https://raw.githubusercontent.com/codu-code/codu/develop/public/images/codu-gradient.png)

You will find the "pull_request_template.md" markdown file in the .github folder.

Screenshots