For over two centuries, the small synagogue standing on top of a hill on a quiet street in the New England seaport community of Newport, R.I., has occupied a unique place in American history -- not only as a part of the American Jewish experience but also as a symbol of religious freedom for all Americans.  It is her "that the right of the individual freely and without governmental restraint to follow the dictate of his own conscience in religious worship could be exercised without danger to the state"