same thing as @republic_of_z's project but with more info
digraph alliance: only certain letters can have that relationship: bl, br, ch, ck, cl, cr, dr, fl, fr, gh, gl, gr, ng, ph, pl, pr, qu, sc, sh, sk, sl, sm, sn, sp, st, sw, th, tr, tw, wh, wr, ai, au, aw, ay, ea, ei, eu, ew, ey, ie, oi, ou, ow, oy the color of the digraph line is the average color of the two letternation's background color (e.g. purple background h and white background t make a lavender digraph line)
