Deploying Project Open Source

Hi,

I have just finished a JavaFX project and deployed it to GitHub.

Now the problem I have is that this is what I pushed to GitHub: https://github.com/shivampaw/cPanelEmailManager

I didn't know how or where to include the libraries (Gson and jlfgr). I figured I should be using a tool like Maven but how can I integrate Maven into an existing project?

For example, with PHP I could add a composer.json and then just run composer install and everything would work. Is there a way with Java to do this and what's the best way to go about it? Also, what files should be uploaded to GitHub when deploying a Java project? Should I upload an executable jar?

Thanks a lot!