Configure rofi-powermenu and lockscreen script

Use rofi-powermenu to show options for suspend,reboot, shutdown,
lockscreen, log out. Can be invoked with <M-backspace>. Other power
option shortcuts have been removed from quick access through sxhkd or
i3. Lockscreen can still be quickly set with <M-x>.

Lockscreen now resides in its own script to provide one source of truth,
and in case it is further customized in the future.

.local/bin/rofi-powermenu

@@ -0,0 +1,30 @@
+#!/usr/bin/env sh
+
+rofi_command="rofi -theme themes/powermenu.rasi"
+
+### Options ###
+power_off=""
+reboot=""
+lock=""
+suspend_btn="鈴"
+logout_btn=""
+# Variable passed to rofi
+
+chosen="$(printf "%s\n%s\n%s\n%s\n%s" "$power_off" "$reboot" "$lock" "$suspend_btn" "$logout_btn" | $rofi_command -dmenu -selected-row 2)"
+case $chosen in
+$power_off)
+  systemctl poweroff
+  ;;
+$reboot)
+  systemctl reboot
+  ;;
+$lock)
+  lockscreen
+  ;;
+$suspend_btn)
+  systemctl suspend
+  ;;
+$logout_btn)
+  i3-msg exit
+  ;;
+esac