Registered voters in Wards 1 and 2 received a postcard in the mail a few weeks back announcing the special election scheduled for Tuesday, Aug. 21 — but in the off chance you quickly tossed in the garbage, allow us to fill you in: In April, D.C. Board of Education member Jeff Smith resigned his seat in protest immediately after the D.C. Council gave preliminary approval to Mayor Adrian Fenty’s school takeover plan, so now…