feat: improve LeapYear README

2_LeapYear/README.md

@@ -13,3 +13,33 @@ Write a function that returns true or false depending on whether its input integ
   - 1996 is a typical leap year
   - 1900 is an atypical common year
   - 2000 is an atypical leap year
+
+| **Input** | **Output** |
+| --------- | ---------- |
+| **1**     | false      |
+| **2**     | false      |
+| **3**     | false      |
+| **4**     | true       |
+| **5**     | false      |
+| **6**     | false      |
+| **7**     | false      |
+| **8**     | true       |
+| **100**   | false      |
+| **200**   | false      |
+| **300**   | false      |
+| **400**   | true       |
+| **500**   | false      |
+| **2001**  | false      |
+| **1996**  | true       |
+| **1900**  | false      |
+| **2000**  | true       |
+
+## Folow TDD rules stryctly
+
+1. Write production code only to pass a failing unit test.
+2. Write no more of a unit test than sufficient to fail (compilation failures are failures).
+3. Write no more production code than necessary to pass the one failing unit test.
+
+## Resources
+
+TestDesiderata by Kent Beck: <https://kentbeck.github.io/TestDesiderata>