Add logo for Gush to help

                   
|Q            |A  |
|---          |---|
|Bug Fix?     |n  |
|New Feature? |y  |
|BC Breaks?   |n  |
|Deprecations?|n  |
|Tests Pass?  |y  |
|Fixed Tickets|   |
|License      |MIT|
|Doc PR       |   |
                   


 Sent using [Gush](https://github.com/gushphp/gush)
I originally used that service, but it did some weird stuff with the logo and the text was also way too large to use in the file