Shell improvements

- `nix-output-monitor`
- `zoxide`
- `zellij`
- `helix` as default editor

flake.nix

@@ -20,6 +20,8 @@
       flake = false;
     };
     helix.url = "github:helix-editor/helix";
+
+    nom.url = "github:maralorn/nix-output-monitor";
   };
   outputs = {self, ...} @ inputs: let
     utils = import ./utils inputs;