improve: add production stage

nginx.conf

@@ -0,0 +1,13 @@
+server {
+    listen 80;
+    server_name localhost;
+    root /usr/share/nginx/html;
+    index index.html;
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+    location /icons/ {
+        try_files $uri =404;
+    }
+    error_page 404 /index.html;
+}