Added knockback effects. Heavy players are now less knocked back, while lighter players are pushed a bit farther! This can be enabled in config.yml by setting effectEnabled.knockback.player to true (enabled by default). Big thanks to 0ct0ber for suggesting this!
Added configuration option to change strength of invidivual effects. Make players get slowed down or knocked back a lot more by configuring an amplifier for each effect. Set the option effectEnabled.speed.amplifier or effectEnabled.knockback.amplifier in config.yml to change it.