Add groups for tools and mushrooms (#2378)

mods/screwdriver/init.lua

@@ -146,6 +146,7 @@ end
 minetest.register_tool("screwdriver:screwdriver", {
 	description = "Screwdriver (left-click rotates face, right-click rotates axis)",
 	inventory_image = "screwdriver.png",
+	groups = {tool = 1},
 	on_use = function(itemstack, user, pointed_thing)
 		screwdriver.handler(itemstack, user, pointed_thing, screwdriver.ROTATE_FACE, 200)
 		return itemstack