fish: Add kitty set-colors abbreviation

This abbreviation is useful when you change your color scheme with
wal and plan to or have multiple kitty windows open (since kitty
itself will still be using the color scheme it initially loaded
from the config file).

fish/.config/fish/config.fish

@@ -73,6 +73,7 @@ if not set -q set_abbr
     abbr b      "feh --bg-fill"             # Change the background
     abbr c      "clear"                     # Because 5 letters is too much
     abbr e      "exit"
+    abbr k      "kitty @ set-colors -c -a ~/.cache/wal/kitty"
     abbr l      "ls -l"
     abbr w      "wal -o ~/.config/wal/done.sh"
     abbr T      "tree"