move nginx test to seperate directory

tests/static_registry/default.nix

@@ -0,0 +1,5 @@
+{
+  nginx = {
+    nginx_7d0cdcc60a96 = { image = "${/home/max/code/nixos/docker/tests/static_registry/nginx/7d0cdcc60a96.tar.gz}"; tag = "nginx:7d0cdcc60a96"; };
+  };
+}