Switch to nginx server (#8)

* test nginx image

* web optimize jpg

* update Readme

* adds docker swarm stack file [CI SKIP]

nginx.conf

@@ -0,0 +1,17 @@
+events {
+  worker_connections 1024;
+}
+http {
+  include mime.types;
+
+  server {
+    listen 80;
+    root /usr/share/nignx/html;
+    index index.html;
+    error_page 404 /404.html;
+
+    location / {
+      try_files $uri $uri/ =404;
+    }
+  }
+}