I should have been clearer but I generally use <> in the documentation as a placeholder, the literal syntax looks more like:
EarthboundBackgrounds setConfiguration myConfigName
or:
JM_EBB.setConfiguration("myConfigName")
depending on whether it is a plugin command or a script call, respectively.
Creating a configuration is much trickier than using one, where the README describes exactly what goes where and the necessary formats to creating a background. Creating a guide would be wonderful and I might eventually do it, but it's pretty low on my priorities because of RL things.