Add script to extract winner handles

This is the first step in making the new CSV file that identifies which
entries each author won. To get a list of all winning handles run

    bin/extract_winner_handles.sh

...which is a very simple pipeline (that could probably be simplified
further) acting on winners.html.

bin/extract_winner_handles.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+grep -o '<A NAME="[^"][A-Za-z_][A-Za-z_]*">' winners.html |sed -e 's,<A NAME=,,g' -e 's/"//g' -e 's/>//g'
+