LuaRocks is package manager for lua.
Defold not need it. But you can use local Lua and LuaRocks to solve some tasks.
For example i use it for map parsing from tiled.
Installing LuaRocks in window pc is a HELL.
I try different ways of installing it. And find guide that worked for me.
Few days ago i try to install it on new pc and find that guide is not available.
So i make a copy of that guide with some small changes.
Maybe someone find it usefull.