Ten years after opening a tiny yoga studio in Saco, Sarah Spiegel has created one of Biddeford's most enduring communities. The Ocean She Built Dark clouds drifted across the sky above Biddeford Pool as Sarah Spiegel stepped into the grass and looked toward the horizon. For 45 minutes, the sun had remained hidden behind a thick layer of blue-gray clouds, leaving only hints of what might happen before nightfall. Then, just before disappearing below the horizon, it found a narr