Add Rubber Goo as replacement for the grinder (#578)

TechDudie

2021-02-09 43acec290067f9aca534647d46ba1f13cfeb377a

 technic/tools/init.lua

@@ -13,6 +13,8 @@
dofile(path.."/chainsaw.lua")
dofile(path.."/tree_tap.lua")
dofile(path.."/sonic_screwdriver.lua")
dofile(path.."/prospector.lua")
dofile(path.."/vacuum.lua")

if minetest.get_modpath("screwdriver") then
   -- compatibility alias