docs: add examples

this is to show how we can use closures in the mad component context. It isn't super pretty because of the async closure, so we need to show the slighly complicated syntax

Signed-off-by: kjuulh <contact@kjuulh.io>

README.md

@@ -41,3 +41,11 @@ async fn main() -> anyhow::Result<()> {
 }
 ```
 
+## Examples
+
+Can be found (here)[crates/mad/examples]
+
+- basic
+- fn
+- signals
+- error_log