Broken link in 04-prompt-engineering-fundamentals

**Describe the bug** The OpenAI link referenced in the explanation of "prompt templates" is broken and returns a 404 error (`Page not found`). **To Reproduce** 1. Open the lesson: 04-prompt-engineering-fundamentals. 2. Locate the sentence about prompt templates: "A prompt template is a pre-defined recipe for a prompt... like this one from OpenAI..." 3. Click the embedded link '[this one from OpenAI](https://platform.openai.com/examples?WT.mc_id=academic-105485-koreyst)'. 4. The OpenAI Platform page loads and displays the "Page not found" error. **Expected behavior** The link should navigate to a valid OpenAI documentation page showing prompt template examples, including interactive prompt components (system/user messages) and API request formats, as described in the lesson text. **Screenshots** <img width="2730" height="941" alt="Image" src="https://github.com/user-attachments/assets/b9ad5207-81c0-410c-91a1-8582ca0a2187" /> **Desktop (please complete the following information):** - OS: Ubuntu 22.04 LTS - Browser: Google Chrome - Version: 126.0.6478.114 (Official Build) (64-bit) **Additional context** This broken link prevents learners from accessing the referenced examples, making it harder to understand the concept of reusable prompt templates.