examples: replace all app.Run(iris.Addr(...)) with app.Listen just for the shake of simplicity, both are doing the same exact thing as it's described on the http listening first example.

Former-commit-id: d20afb2e899aee658a8e0ed1693357798df93462

_examples/apidoc/yaag/main.go

@@ -51,5 +51,5 @@ func main() {
 	//
 	// Example usage:
 	// Visit all paths and open the generated "apidoc.html" file to see the API's automated docs.
-	app.Run(iris.Addr(":8080"))
+	app.Listen(":8080")
 }