This is a simple playground for learning about LOVE's particle system. It's not a proper particle system editor, which would include support for emitter lifetimes, multiple particle systems, loading/saving, etc.
It won't as it is, partly because LOVE 0.11.0 adds some new methods to ParticleSystems, "set/getAreaSpreadAngle" and "set/getAreaSpreadIsRelativeDirection". I suspect it won't be long until LOVE 0.11.0 is released though.