Add nix-shell for local Zola development

shell.nix

@@ -0,0 +1,38 @@
+{ pkgs ? import <nixpkgs> {} }:
+
+pkgs.mkShell {
+  buildInputs = with pkgs; [
+    zola
+    git
+  ];
+
+  shellHook = ''
+    # ===================
+    # DEV COMMANDS
+    # ===================
+    dev-up() {
+      zola serve --interface 0.0.0.0 --port 1111 "$@"
+    }
+
+    dev-build() {
+      zola build
+    }
+
+    # ===================
+    # WELCOME MESSAGE
+    # ===================
+    echo ""
+    echo "================================================="
+    echo "           lvl0-website Dev Environment          "
+    echo "================================================="
+    echo ""
+    echo "  Zola: $(zola --version)"
+    echo ""
+    echo "Commands:"
+    echo "  dev-up       Start zola serve (live reload)"
+    echo "  dev-build    Build static site to /public"
+    echo ""
+    echo "Site: http://localhost:1111"
+    echo ""
+  '';
+}