add hostname to background image

nixos/components/gui/home-manager/i3.nix

@@ -33,7 +33,11 @@ let
       ${pkgs.findutils}/bin/xargs \
         ${pkgs.polygon-art.polygon-art}/bin/rings \
           /dev/shm/background.png && \
-        ${pkgs.feh}/bin/feh --bg-scale /dev/shm/background.png
+        ${pkgs.imagemagick}/bin/convert /dev/shm/background.png \
+          -font ${pkgs.ubuntu_font_family}/share/fonts/ubuntu/UbuntuMono-B.ttf \
+          -gravity Center -pointsize 30 -annotate 0 '${config.networking.hostName}' \
+          /dev/shm/background_with_text.png && \
+        ${pkgs.feh}/bin/feh --bg-scale /dev/shm/background_with_text.png
   '';
 
 in