implemented poor man's pkill (2)

disabled SC2009

SC2009 (info): Consider using pgrep instead of grepping ps output

.tmux.conf

@@ -246,6 +246,7 @@ run 'cut -c3- "$TMUX_CONF" | sh -s _apply_configuration'
 #       }
 #       ;;
 #     *)
+#       # shellcheck disable=SC2009
 #       _pkillf() {
 #         while IFS= read -r pid; do
 #           kill "$pid" || true