Update utoipa config example

Author: juhaku

examples/config-test-crate

@@ -0,0 +1,6 @@
+# utoipa-config-test
+
+This example demonstrates global Rust type aliases in utoipa project. 
+Check out `main.rs` and `build.rs` and then run `cargo run`.
+
+Browse the [project files here](../../utoipa-config/config-test-crate/).