add colors for dunst (#393)

Added TokyoNight colorscheme for [dunst](https://dunst-project.org/) notification daemon.

lua/tokyonight/extra/dunst.lua

@@ -0,0 +1,32 @@
+local util = require("tokyonight.util")
+
+local M = {}
+
+--- @param colors ColorScheme
+function M.generate(colors)
+  local dunst = util.template(
+    [[
+# TokyoNight colors for dunst
+# For more configuraion options see https://github.com/dunst-project/dunst/blob/master/dunstrc
+
+[urgency_low]
+    background = "${bg_dark}"
+    foreground = "${fg}"
+	frame_color = "${fg}"
+
+[urgency_normal]
+    background = "${bg}"
+    foreground = "${fg}"
+	frame_color = "${fg}"
+
+[urgency_critical]
+    background = "${bg_highlight}"
+    foreground = "${error}"
+    frame_color = "${error}"
+]],
+    colors
+  )
+  return dunst
+end
+
+return M