Add .luacheckrc

- Removes unused variable

.luacheckrc

@@ -0,0 +1,30 @@
+std = "lua51+minetest"
+unused_args = false
+allow_defined_top = true
+max_line_length = 999
+
+stds.minetest = {
+	read_globals = {
+		"DIR_DELIM",
+		"minetest",
+		"core",
+		"dump",
+		"vector",
+		"nodeupdate",
+		"VoxelManip",
+		"VoxelArea",
+		"PseudoRandom",
+		"ItemStack",
+		"default",
+		table = {
+			fields = {
+				"copy",
+			},
+		},
+	}
+}
+
+read_globals = {
+	"default",
+	"moreores",
+}