Docs: Update behind_proxy.md to include HTTPS and URL rewrite example (#21832)

docs/sources/installation/behind_proxy.md

@@ -37,10 +37,11 @@ domain = foo.bar
 
 Nginx is a high performance load balancer, web server and reverse proxy: https://www.nginx.com/
 
+#### Nginx configuration with HTTP and Reverse Proxy enabled
 ```bash
 server {
   listen 80;
-  root /usr/share/nginx/www;
+  root /usr/share/nginx/html;
   index index.html index.htm;
 
   location / {
@@ -49,6 +50,44 @@ server {
 }
 ```
 
+### Grafana configuration with hosting HTTPS in Nginx (ex https://foo.bar)
+
+```bash
+[server]
+domain = foo.bar
+root_url = https://foo.bar
+```
+
+#### Nginx configuration with HTTPS, Reverse Proxy, HTTP to HTTPS redirect and URL re-writes enabled
+
+Instead of http://foo.bar:3000/?orgId=1, this configuration will redirect all HTTP requests to HTTPS and re-write the URL so that port 3000 isn't visible and will result in https://foo.bar/?orgId=1
+
+```bash
+server {
+  listen 80;
+  server_name foo.bar;
+  return 301 https://foo.bar$request_uri;
+}
+
+server {
+  listen 443 ssl http2;
+  server_name foo.bar;
+  root /usr/share/nginx/html;
+  index index.html index.htm;
+  ssl_certificate /etc/nginx/certs/foo_bar.crt;
+  ssl_certificate_key /etc/nginx/certs/foo_bar_decrypted.key;
+  ssl_protocols TLSv1.2;
+  ssl_ciphers HIGH:!aNULL:!MD5;
+
+  location / {
+   rewrite /(.*) /$1  break;
+   proxy_pass http://localhost:3000/;
+   proxy_redirect off;
+   proxy_set_header Host $host;
+  }
+}
+```
+
 ### Examples with **sub path** (ex http://foo.bar/grafana)
 
 #### Grafana configuration with sub path