updated table formatting in readme

Author: jeremymanning

README.md

@@ -2,13 +2,13 @@
 
 Each day (ideally) we'll attempt the daily [leetcode](https://leetcode.com) problem.  We'll make a new folder for each day's problem.  Anyone who wants can submit a markdown file, iPython notebook, etc. with their notes, questions, solutions, test cases, or other problem-related files.
 
-# Problems we've attempted thus far:
+# Problems we've attempted so far:
 
-| Date         | Problem                                                                                                     | Link to notes                                                                                             | Difficulty |
+| 📆 Date         | ⚙️ Problem                                                                                                     | 📝 Link to notes                                                                                             | ⚠️ Difficulty |
 |--------------|-------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------|------------|
-| July 1, 2024 | [350](https://leetcode.com/problems/intersection-of-two-arrays-ii/)                                         | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/350)                     | Easy       |
-| July 2, 2024 | [1509](https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves/) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/1509)                    | Medium     |
-| July 3, 2024 | [2181](https://leetcode.com/problems/merge-nodes-in-between-zeros/)                                         | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/2181)                    | Medium     |
+| July 1, 2024 | [350](https://leetcode.com/problems/intersection-of-two-arrays-ii/)                                         | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/350)                     | 🟢  Easy        |
+| July 2, 2024 | [1509](https://leetcode.com/problems/minimum-difference-between-largest-and-smallest-value-in-three-moves/) | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/1509)                    | 🟡  Medium      |
+| July 3, 2024 | [2181](https://leetcode.com/problems/merge-nodes-in-between-zeros/)                                         | [Click here](https://github.com/ContextLab/leetcode-solutions/tree/main/problems/2181)                    | 🟡  Medium      |
 
 # Join our discussion!