[docs] reverse-proxy: nginx: add two setups for STATIC_URL_PREFIX

Signed-off-by: Jakob Ackermann <[email protected]>

Author: das7pad

docs/content/doc/usage/reverse-proxies.en-us.md

@@ -44,6 +44,74 @@ server {
 
 Then set `[server] ROOT_URL = http://git.example.com/git/` in your configuration.
 
+##  Using Nginx as a reverse proxy and serve static resources directly
+We can tune the performance in splitting requests into categories static and dynamic. 
+
+CSS files, JavaScript files, images and web fonts are static content.
+The front page, a repository view or issue list is dynamic content.
+
+Nginx can serve static resources directly and proxy only the dynamic requests to gitea.
+Nginx is optimized for serving static content, while the proxying of large responses might be the opposite of that
+ (see https://serverfault.com/q/587386).
+
+Download a snap shot of the gitea source repository to `/path/to/gitea/`.
+
+We are only interested in the `public/` directory and you can delete the rest.
+
+Depending on the scale of your user base, you might want to split the traffic to two distinct servers,
+ or use a cdn for the static files.
+
+### using a single node and a single domain
+
+Set `[server] STATIC_URL_PREFIX = /_/static` in your configuration.
+
+```
+server {
+    listen 80;
+    server_name git.example.com;
+
+    location /_/static {
+        alias /path/to/gitea/public;
+    }
+
+    location / {
+        proxy_pass http://localhost:3000;
+    }
+}
+```
+
+### using two nodes and two domains
+
+Set `[server] STATIC_URL_PREFIX = http://cdn.example.com/gitea` in your configuration.
+
+```
+# application server running gitea
+server {
+    listen 80;
+    server_name git.example.com;
+
+    location / {
+        proxy_pass http://localhost:3000;
+    }
+}
+```
+
+```
+# static content delivery server
+server {
+    listen 80;
+    server_name cdn.example.com;
+
+    location /gitea {
+        alias /path/to/gitea/public;
+    }
+
+    location / {
+        return 404;
+    }
+}
+```
+
 ## Using Apache HTTPD as a reverse proxy
 
 If you want Apache HTTPD to serve your Gitea instance, you can add the following to your Apache HTTPD configuration (usually located at `/etc/apache2/httpd.conf` in Ubuntu):