Adds three darker variants of support beams to the game.

Stained support beams are crafted by sealing any support beams in a barrel with weak tannin.

Dark stained support beams are crafted by sealing any support beams in a barrel with strong tannin, or stained beams in weak tannin once more.

Black support beam are crafted by sealing any support beams in a barrel with black dye, or dark stained beams in strong tannin once more.

Note: the fourth beams in the images (the lightest ones) are ebony wood beams, the darkest wood beams in the vanilla game.