added nginx config file in docs

Author: leoBitto

docs/flaskapp

@@ -0,0 +1,12 @@
+server {
+    listen 80;
+    server_name _;
+
+    location / {
+        proxy_pass http://127.0.0.1:5000;
+        proxy_set_header Host $host;
+        proxy_set_header X-Real-IP $remote_addr;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
+    }
+}