runCommand -package:wai-app-static -package:libmpd -package:io-streams -package:shake-plus -package:beam-migrate is:exact -package:graphviz -package:cabal-install -package:options -package:hledger -package:mongoDB -package:process -package:github-release -package:pandoc-plot -package:Cabal
Given a list of command/action pairs, prompt the user to choose a
command using dmenu and return the corresponding action.