The Melee and Gun grip scripts are helper tools to make it easier to handle more advanced interactions with VR. They do not “create” guns or melee objects for you, however they do provide a set of useful functions and interactions to make doing so trivial.
ProjectSettings/VRExpansionPlugin has some global settings for them (for the Gun tools it has virtual stock and smoothing settings, and for the melee script it has physics surface damage and penetration settings).
#I still need to flesh out the descriptions here