How to set server banner/description?

As a server owner, how do I set a server banner/image and description?

[editline]12th September 2015[/editline]

Ok so I figured out you add +server.description “description goes here” to your server command line to set the description. The line to add a server header image is server.headerimage. But where do I drop the image I want to use? I assume in one of the server folders, just not sure which one.

Havent tried it yet but my guess is to make a folder and direct to it much like other files are referred to such as the -cfg serverdata/cfg/serverconfig.cfg is done in my hosting panel.