openCustoms export for other scripts

[judeiras]

Description

I wrote a export that allows the vehicle tune menu to be opened by an external script like adminmenu.
It can be added to here.

Checklist

• I have personally loaded this code into an updated Qbox project and checked all of its functionality.
• My pull request fits the contribution guidelines & code conventions.

[mafewtm]

You need to fix this before it can be merged. You've removed all the necessary github files.