added nix action

.github/workflows/docker.yml

@@ -2,22 +2,22 @@ name: Docker
 
 on:
     push:
-    branches: [ "main" ]
+        branches: ["main"]
         # paths:
         #   - 'Cargo.toml'
     pull_request:
-    branches: [ "main" ]
+        branches: ["main"]
 
 env:
     CARGO_TERM_COLOR: always
 
 jobs:
     build:
-
         runs-on: ubuntu-latest
 
         steps:
             - uses: actions/checkout@v4
+            - uses: hustcer/setup-nu@v3
             - uses: cachix/install-nix-action@v31
               with:
                   nix_path: nixpkgs=channel:nixos-unstable