Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/sum-digits-of-an-integer.md

@@ -5,54 +5,70 @@ challengeType: 5
 forumTopicId: 302331
 ---
 
-## Description
+# --description--
 
-<section id='description'>
 Write a function that takes a string as a parameter. This string represents a number that can be in any base (less than 37) and return the sum of its digits.
+
 <ul>
   <li><b>1</b><sub>10</sub> sums to <b>1</b></li>
   <li><b>1234</b><sub>10</sub> sums to <b>10</b></li>
   <li><b>fe</b><sub>16</sub> sums to <b>29</b></li>
   <li><b>f0e</b><sub>16</sub> sums to <b>29</b></li>
 </ul>
-</section>
 
-## Instructions
+# --hints--
 
-<section id='instructions'>
+`sumDigits` should be a function.
 
-</section>
-
-## Tests
-
-<section id='tests'>
-
-```yml
-tests:
-  - text: <code>sumDigits</code> should be a function.
-    testString: assert(typeof sumDigits == 'function');
-  - text: <code>sumDigits("1")</code> should return a number.
-    testString: assert(typeof sumDigits("1") == 'number');
-  - text: <code>sumDigits("1")</code> should return <code>1</code>.
-    testString: assert.equal(sumDigits("1"), 1);
-  - text: <code>sumDigits("12345")</code> should return <code>15</code>.
-    testString: assert.equal(sumDigits("12345"), 15);
-  - text: <code>sumDigits("254")</code> should return <code>11</code>.
-    testString: assert.equal(sumDigits("254"), 11);
-  - text: <code>sumDigits("fe")</code> should return <code>29</code>.
-    testString: assert.equal(sumDigits("fe"), 29);
-  - text: <code>sumDigits("f0e")</code> should return <code>29</code>.
-    testString: assert.equal(sumDigits("f0e"), 29);
-  - text: <code>sumDigits("999ABCXYZ")</code> should return <code>162</code>.
-    testString: assert.equal(sumDigits("999ABCXYZ"), 162);
+```js
+assert(typeof sumDigits == 'function');
 ```
 
-</section>
+`sumDigits("1")` should return a number.
 
-## Challenge Seed
+```js
+assert(typeof sumDigits('1') == 'number');
+```
 
-<section id='challengeSeed'>
-<div id='js-seed'>
+`sumDigits("1")` should return `1`.
+
+```js
+assert.equal(sumDigits('1'), 1);
+```
+
+`sumDigits("12345")` should return `15`.
+
+```js
+assert.equal(sumDigits('12345'), 15);
+```
+
+`sumDigits("254")` should return `11`.
+
+```js
+assert.equal(sumDigits('254'), 11);
+```
+
+`sumDigits("fe")` should return `29`.
+
+```js
+assert.equal(sumDigits('fe'), 29);
+```
+
+`sumDigits("f0e")` should return `29`.
+
+```js
+assert.equal(sumDigits('f0e'), 29);
+```
+
+`sumDigits("999ABCXYZ")` should return `162`.
+
+```js
+assert.equal(sumDigits('999ABCXYZ'), 162);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function sumDigits(n) {
@@ -60,12 +76,7 @@ function sumDigits(n) {
 }
 ```
 
-</div>
-</section>
-
-## Solution
-
-<section id='solution'>
+# --solutions--
 
 ```js
 function sumDigits(n) {
@@ -75,5 +86,3 @@ function sumDigits(n) {
   return s;
 }
 ```
-
-</section>