Add time notifier bmo nag

dotfiles/config/bmo/nag.ini

 [nag.stream]
-    master = event overdue projsum active week stconflict wttr
+    master = event overdue projsum active week stconflict wttr timenow
+
+[nag.def.timenow]
+    command = date --rfc-3339=seconds
+    expiry = 10 minutes
+    term-color = magenta
 
 [nag.def.event]
     command = task rc.verbose=nothing list +event due.before:now+2w -ACTIVE