Add Docker setup for Nginx serving built Node app

Introduce a multi-stage Dockerfile to build and serve a Node.js application using Nginx. Define a custom Nginx configuration for optimized static file handling and enable gzip compression.

.docker/app/nginx/nginx.conf

@@ -0,0 +1,51 @@
+user  nginx;
+worker_processes  1;
+
+error_log  /var/log/nginx/error.log warn;
+pid        /var/run/nginx.pid;
+
+events {
+  worker_connections  1024;
+}
+
+http {
+    include       /etc/nginx/mime.types;
+    default_type  application/octet-stream;
+
+    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
+                      '$status $body_bytes_sent "$http_referer" '
+                      '"$http_user_agent" "$http_x_forwarded_for"';
+
+    access_log  /var/log/nginx/access.log  main;
+
+    gzip on;
+    gzip_comp_level 6;
+    gzip_http_version 1.1;
+    gzip_proxied any;
+    gzip_min_length 256;
+    gzip_types text/plain text/css application/javascript application/x-javascript application/xml application/xml+rss application/atom+xml image/svg+xml;
+
+    sendfile        on;
+    tcp_nopush     on;
+    tcp_nodelay    on;
+    keepalive_timeout  65;
+    types_hash_max_size 2048;
+
+    include /etc/nginx/sites-enabled/*;
+
+    server {
+        listen       80;
+        server_name  _;
+
+        location / {
+            root   /usr/share/nginx/html;
+            index  index.html;
+            try_files $uri $uri/ /index.html;
+        }
+
+        error_page   500 502 503 504  /50x.html;
+        location = /50x.html {
+            root   /usr/share/nginx/html;
+        }
+    }
+}