docs: remove all usages of static closure syntax and update readme

docs/guide/src/elements/conditional_rendering.md

@@ -81,11 +81,6 @@ fn App(cx: Scope)-> Element {
 }
 ```
 
-This syntax even enables us to write a one-line component:
-```rust
-static App: Component = |cx| rsx!(cx, "hello world!");
-```
-
 Alternatively, for match statements, we can just return the builder itself and pass it into a final, single call to `cx.render`:
 
 ```rust