reorganize the fullstack docs

docs/guide/src/en/fullstack/server_functions.md

@@ -0,0 +1,31 @@
+# Communicating with the server
+
+`dixous-server` provides server functions that allow you to call an automatically generated API on the server from the client as if it were a local function.
+
+To make a server function, simply add the `#[server(YourUniqueType)]` attribute to a function. The function must:
+
+- Be an async function
+- Have arguments and a return type that both implement serialize and deserialize (with [serde](https://serde.rs/)).
+- Return a `Result` with an error type of ServerFnError
+
+You must call `register` on the type you passed into the server macro in your main function before starting your server to tell Dioxus about the server function.
+
+Let's continue building on the app we made in the [getting started](./getting_started.md) guide. We will add a server function to our app that allows us to double the count on the server.
+
+First, add serde as a dependency:
+
+```shell
+cargo add serde
+```
+
+Next, add the server function to your `main.rs`:
+
+```rust
+{{#include ../../../examples/server_function.rs}}
+```
+
+Now, build your client-side bundle with `dioxus build --features web` and run your server with `cargo run --features ssr`. You should see a new button that multiplies the count by 2.
+
+## Conclusion
+
+That's it! You've created a full-stack Dioxus app. You can find more examples of full-stack apps and information about how to integrate with other frameworks and desktop renderers in the [dioxus-fullstack examples directory](https://github.com/DioxusLabs/dioxus/tree/master/packages/server/examples).