Revise README for updated application demos and tutorials

Updated links and descriptions in the README to reflect current resources.

README.markdown

@@ -16,7 +16,7 @@ Cappuccino faithfully implements the proven design patterns of NeXTSTEP/Apple's
 
 Cappuccino is not intended for building simple websites. It is for building **applications**—especially complex, data-rich, line-of-business tools where productivity and user experience are paramount.
 
-*   **💻 True Desktop Behavior, Out-of-the-Box:** Applications built with Cappuccino behave like native desktop software by default. This includes a rich palette of UI controls, **full keyboard navigation and focus management**, and **multi-level undo/redo support** — as you can see in this [Demo application](https://ansb.uniklinik-freiburg.de/UIBuilder/index.html). Also take a look at the [Kitchen Sink demo](https://ansb.uniklinik-freiburg.de/ThemeKitchenSinkA3/).
+*   **💻 True Desktop Behavior, Out-of-the-Box:** Applications built with Cappuccino behave like native desktop software by default. This includes a rich palette of UI controls, **full keyboard navigation and focus management**, and **multi-level undo/redo support** — as you can see in this [Showcase application](https://ansb.uniklinik-freiburg.de/ThemeKitchenSinkA3). Also take a look at the [Cookbook tutorial](https://cappuccino-cookbook.5apps.com/).
 *   **🚀 Incredible Productivity:** Less code is needed. High-level abstractions and a powerful object-oriented model mean development is focused on application logic, not browser quirks.
 *   **🏛️ Stable & Mature:** Built on decades of proven API design from Cocoa®, Cappuccino provides a stable foundation, free from the churn common in the JavaScript ecosystem.
 *   **🧱 True Object-Oriented Architecture:** Objective-J's message-passing architecture promotes loose coupling and clean design, making large-scale applications easier to build and maintain.