Add WG Tunnel as the example of an outbound proxy

docs/adguard-for-android/solving-problems/outbound-proxy.md

@@ -155,6 +155,28 @@ You should remove Shadowsocks app from filtering before setting up the process (
     Proxy host | *127.0.0.1*
     Proxy port | *7891*
 
+### How to use AdGuard with WG Tunnel
+
+*The proxy mode was added in version 4.0. We presume that you already have WG Tunnel installed on your device and have added the WireGuard configuration.*
+
+1. Open WG Tunnel and go to **Settings** (the cog wheel at the bottom) → **App Mode** → **Proxy (experimental)**. This will set WG Tunnel to proxy mode.
+
+1. Open AdGuard and go to **App management**. Choose **WG Tunnel** and disable **Route traffic through AdGuard**. This will eliminate traffic looping.
+
+1. Then go to **Settings** → **Filtering** → **Network** → **Proxy** → **Proxy server**.
+
+1. Tap **Add proxy server** and fill in the fields:
+
+    Field      |  Value
+    -------    | ---------
+    Proxy type | *SOCKS5*
+    Proxy host | *127.0.0.1*
+    Proxy port | *25344*
+
+1. Tap **Save and select**.
+
+1. Enable the main proxy switch and AdGuard protection to route your device’s traffic through the proxy.
+
 ## Limitations
 
 However, at least one factor may prevent certain traffic from being routed through the outbound proxy, even after configuring the AdGuard proxy settings. That would be if the app itself isn't configured to send its traffic through AdGuard. To do it, you need to proceed to **App management**, choose the app, and turn on **Route traffic through AdGuard**.