docs(installation): add reverse proxy documentation

* chore: add instructions how to run tabby behind nginx reverse proxy

website/docs/quick-start/installation/reverse-proxy.mdx

@@ -0,0 +1,30 @@
+---
+sidebar_position: 4
+---
+
+# Reverse Proxy
+
+This guide explains how to use Tabby behind a reverse proxy.
+
+import Tabs from '@theme/Tabs';
+import TabItem from '@theme/TabItem';
+
+<Tabs>
+  <TabItem value="nginx" label="Nginx" default>
+
+    Add the following to your Nginx configuration:
+
+    ```
+    location / {
+        proxy_pass       http://localhost:8080;
+        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_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection "upgrade";
+    }
+    ```
+
+  </TabItem>
+</Tabs>