Put the olive oil into a large, heavy skillet over medium heat. Season the chicken thighs with salt and pepper and add them to the skillet, skin side down. Cook them like this, without moving them, until the fat has rendered out and the skin is deep golden brown and crisp, 15 to 30 minutes. Fiddle with the heat, reducing it to medium-low if the skin begins to burn before it gets evenly golden brown. Turn the thighs over and stir the preserved lemon rind into the fat in the skillet. Continue cooking the thighs until the meat closest to the bone is cooked through, about 15 minutes more. Serve the thighs and lemony pan drippings with the lemon wedges.