sxhkd, polybar, dunst: Add setting no disturb mode

By invoking key combination fn+F9 (XF86Search button), we can quiet
dunst notifications.

This change will be picked up by polybar and a small do not disturb
symbol is shown in the top bar (a tiny moon).

Both scripts are very simple and make use of a temporary file, so a
little brittle but workable.

polybar/.config/polybar/config

@@ -59,7 +59,7 @@ module-margin-left = 2
 
 modules-left = sxhkdmode workspaces pomo papersdue
 modules-center = music date
-modules-right = networkspeed mail weather archupdates cpu temp volume battery
+modules-right = dunstpaused networkspeed mail weather archupdates cpu temp volume battery
 ; do not use offsets for the bar, would only work with override-redirect
 ; and will mess up tray https://github.com/polybar/polybar/issues/1355
 tray-position = right
@@ -250,6 +250,13 @@ format-prefix = " "
 interval = 120
 format-underline = ${colors.primary}
 
+[module/dunstpaused]
+type = custom/script
+exec = sed -e 's/true/⏾/' -e 's/false//' /tmp/dunstpaused
+exec-if = [ -f /tmp/dunstpaused ]
+tail = true
+format-underline = ${colors.primary}
+
 [module/mail]
 type = custom/script
 exec = echo "$( [ $(systemctl --user --property=ActiveState show mbsync.timer) = 'ActiveState=active' ] && echo "" || echo "" ) $(notmuch count tag:inbox and tag:unread)"

sxhkd/.config/sxhkd/sxhkdrc

@@ -25,6 +25,9 @@ XF86AudioMute
 XF86Audio{LowerVolume,RaiseVolume}
   control-volume {down, up}
 
+XF86Search
+  dunstctl set-paused toggle && echo "$(dunstctl is-paused)" > /tmp/dunstpaused
+
 # Open terminal emulator (the variable gets set in sh module basic env vars)
 super + Return
   $TERMINAL