Update README with LeetCode Daily Challenge

Author: jeremymanning

README.md

@@ -21,6 +21,7 @@ This means you'll always find an AI-generated solution to compare with or learn
 | 📆 Date         | ⚙️ Problem                                                                                                     | 📝 Link to notes                                                                                             | 🚦 Difficulty |
 |--------------|-------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------|------------|
 | December 1, 2025 | [2141](https://leetcode.com/problems/maximum-running-time-of-n-computers/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/2141) | 🔴 Hard |
+| December 2, 2025 | [3623](https://leetcode.com/problems/count-number-of-trapezoids-i/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/3623) | 🟡 Medium |
 
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