feat: switch to fish as an interactive shell

Now that it is written in Rust I am interested!

modules/hm/default.nix

@@ -58,6 +58,11 @@ in
           git = true;
           icons = "auto";
         };
+        # Shell
+        fish = {
+          enable = true;
+          preferAbbrs = true; # when defining an alias, prefer instead to define an abbreviation
+        };
         # GnuPG
         gpg = {
           enable = true;
@@ -75,16 +80,6 @@ in
         ssh.enable = true;
         # cd replacement
         zoxide.enable = true;
-        # Shell
-        zsh = {
-          enable = true;
-          autosuggestion.enable = true;
-          enableCompletion = true;
-          autocd = true;
-          dotDir = ".config/zsh";
-          history.path = "${config.xdg.dataHome}/zsh/zsh_history";
-          syntaxHighlighting.enable = true;
-        };
       };
 
       services = {

modules/hm/gui/default.nix

@@ -129,13 +129,13 @@ in
       # PDF reader
       zathura.enable = true;
       # Auto start sway
-      zsh.loginExtra =
-        lib.optionalString cfg.sway.autostart # sh
+      fish.loginShellInit =
+        lib.optionalString cfg.sway.autostart # fish
           ''
             # Start Sway on login to TTY 1
-            if [ "$TTY" = /dev/tty1 ]; then
+            if test "$(tty)" = /dev/tty1
               exec sway
-            fi
+            end
           '';
     };
     services = {