Add docu for TP loader

Author: VladislavAtanasov95

docs-java/features/connectivity/008-transparent-proxy.mdx

@@ -211,6 +211,52 @@ try {
 
 For more information, see [Troubleshooting](https://help.sap.com/docs/connectivity/sap-btp-connectivity-cf/transparent-proxy-troubleshooting)
 
+## Transparent Proxy Loader
+
+The `TransparentProxy` class is a `DestinationLoader` that enables routing all destination traffic through a single registered gateway host. This provides a centralized approach to proxy configuration where all destination requests are automatically routed through the configured gateway.
+
+### Key Features
+
+- **Single gateway registration** - only one proxy can be registered at a time
+- **Host validation** - ensures hosts don't contain paths and are reachable
+- **Automatic scheme normalization** - defaults to HTTP if no scheme provided
+- **Network connectivity validation** before registration
+- **Thread safety considerations** - uses static state and should be registered during application initialization
+
+### Registration Methods
+
+#### Register with Default Port
+
+Register a transparent proxy gateway using the default port 80:
+
+```java
+// Register with default port 80
+TransparentProxy.register("gateway.svc.cluster.local");
+```
+
+The host will be validated for reachability and must not contain any path components. If no scheme is provided, HTTP will be used by default.
+
+#### Register with Custom Port
+
+Register a transparent proxy gateway with a specified port:
+
+```java
+// Register with custom port
+TransparentProxy.register("http://gateway.svc.cluster.local", 8080);
+```
+
+The final URI will be constructed as: `<normalized-host>:<port>`
+
+### Usage Example
+
+```java
+// Register the transparent proxy during application initialization
+TransparentProxy.register("gateway.svc.cluster.local", 8080);
+
+// All subsequent destination requests will be routed through the registered gateway
+Destination destination = DestinationAccessor.getDestination("my-destination");
+```
+
 ## Related Documentation
 
 - [HTTP Client](http-client) - For using destinations with HTTP clients