Feat: add new Markdown parser (#39800)

and change all the challenges to new `md` format.

curriculum/challenges/english/08-data-analysis-with-python/numpy/mathematics.md

@@ -5,45 +5,44 @@ challengeType: 11
 videoId: 7txegvyhtVk
 ---
 
-## Description
+# --question--
 
-<section id='description'>
-</section>
+## --text--
 
-## Tests
+What is the value of `b` after running the following code?
 
-<section id='tests'>
+```py
+import numpy as np
 
-````yml
-question:
-  text: |
-    What is the value of `b` after running the following code?
+a = np.array(([1, 2, 3, 4, 5], [6, 7, 8, 9, 10]))
+b = np.max(a, axis=1).sum()
+```
 
-    ```py
-    import numpy as np
+## --answers--
 
-    a = np.array(([1, 2, 3, 4, 5], [6, 7, 8, 9, 10]))
-    b = np.max(a, axis=1).sum()
-    ```
+```py
+10
+```
 
-  answers:
-    - |
-      ```py
-      10
-      ```
-    - |
-      ```py
-      7
-      ```
-    - |
-      ```py
-      5
-      ```
-    - |
-      ```py
-      15
-      ```
-  solution: 4
-````
+---
+
+```py
+7
+```
+
+---
+
+```py
+5
+```
+
+---
+
+```py
+15
+```
+
+## --video-solution--
+
+4
 
-</section>