Added my set of helper scripts. Removes the spell makefile target as it was not use{d,ful} anyway. Btw: I should have ran script/doubles before I printed the document. :-/

#!/bin/sh
#
# print frequency of words

deroff "$@" | tr -cs A-Za-z '\012' | tr A-Z a-z |
	sort | uniq -c | sort -nr | sed 20q