Add ilinks check to GH Actions

.github/workflows/main.yml

@@ -29,14 +29,4 @@ jobs:
         with:
           nix_path: nixpkgs=channel:nixos-unstable
       - run: "nix-shell --run 'nanoc --env=prod'"
-      - uses: actions/checkout@v2
-
-      # Runs a single command using the runners shell
-      - name: Run a one-line script
-        run: echo Hello, world!
-
-      # Runs a set of commands using the runners shell
-      - name: Run a multi-line script
-        run: |
-          echo Add other actions to build,
-          echo test, and deploy your project.
+      - run: "nix-shell --run 'nanoc --env=prod check --deploy'"