shell/fzf: add bin/fzf-kill

shell/fzf/bin/fzf-kill

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+# Interactively select a process to kill.
+
+pid=$(ps -ef | sed 1d | gui-fzf -m | awk '{print $2}')
+
+if [[ $pid ]]; then
+    xargs kill -${1:-9} <<< "$pid"
+fi