A Batavia nonprofit that grew from a single fitness studio room is now serving more than 200 students a week, and a new $20,000 grant is helping it reach even further.Letters to Literacy, a Batavia nonprofit focused on literacy and phonics, has grown from a 300-square-foot room at Anchor Fitness into a 4,300-square-foot building where students receive reading tutoring, math support, speech and occupational therapy and high school writing instruc…