Update README with LeetCode Daily Challenge

Author: jeremymanning

README.md

@@ -75,6 +75,7 @@ Each day (ideally) we'll attempt the daily [leetcode](https://leetcode.com) prob
 | September 2, 2024 | [1894](https://leetcode.com/problems/find-the-student-that-will-replace-the-chalk/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/1894) | 🟡 Medium |
 | September 3, 2024 | [1945](https://leetcode.com/problems/sum-of-digits-of-string-after-convert/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/1945) | 🟢 Easy |
 | September 4, 2024 | [874](https://leetcode.com/problems/walking-robot-simulation/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/874) | 🟡 Medium |
+| September 5, 2024 | [2028](https://leetcode.com/problems/find-missing-observations/description/?envType=daily-question) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/2028) | 🟡 Medium |
 
 # Join our discussion!