Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/stern-brocot-sequence.md

@@ -5,10 +5,10 @@ challengeType: 5
 forumTopicId: 302324
 ---
 
-## Description
+# --description--
+
+For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the [Fibonacci sequence](<https://rosettacode.org/wiki/Fibonacci sequence>).
 
-<section id='description'>
-For this task, the Stern-Brocot sequence is to be generated by an algorithm similar to that employed in generating the <a href="https://rosettacode.org/wiki/Fibonacci sequence" target="_blank">Fibonacci sequence</a>.
 <ol>
   <li>The first and second members of the sequence are both 1:</li>
     <ul><li>1, 1</li></ul>
@@ -32,42 +32,58 @@ For this task, the Stern-Brocot sequence is to be generated by an algorithm simi
     <ul><li>1, 1, 2, 1, 3, 2</li></ul>
   <li>Consider the next member of the series, (the fourth member i.e. 1)</li>
 </ol>
-</section>
 
-## Instructions
+# --instructions--
 
-<section id='instructions'>
 Create a function that returns the $ n^{th} $ member of the sequence using the method outlined above.
-</section>
 
-## Tests
+# --hints--
 
-<section id='tests'>
+`sternBrocot` should be a function.
 
-```yml
-tests:
-  - text: <code>sternBrocot</code> should be a function.
-    testString: assert(typeof sternBrocot == 'function');
-  - text: <code>sternBrocot(2)</code> should return a number.
-    testString: assert(typeof sternBrocot(2) == 'number');
-  - text: <code>sternBrocot(2)</code> should return <code>3</code>.
-    testString: assert.equal(sternBrocot(2), 3);
-  - text: <code>sternBrocot(3)</code> should return <code>5</code>.
-    testString: assert.equal(sternBrocot(3), 5);
-  - text: <code>sternBrocot(5)</code> should return <code>11</code>.
-    testString: assert.equal(sternBrocot(5), 11);
-  - text: <code>sternBrocot(7)</code> should return <code>19</code>.
-    testString: assert.equal(sternBrocot(7), 19);
-  - text: <code>sternBrocot(10)</code> should return <code>39</code>.
-    testString: assert.equal(sternBrocot(10), 39);
+```js
+assert(typeof sternBrocot == 'function');
 ```
 
-</section>
+`sternBrocot(2)` should return a number.
 
-## Challenge Seed
+```js
+assert(typeof sternBrocot(2) == 'number');
+```
 
-<section id='challengeSeed'>
-<div id='js-seed'>
+`sternBrocot(2)` should return `3`.
+
+```js
+assert.equal(sternBrocot(2), 3);
+```
+
+`sternBrocot(3)` should return `5`.
+
+```js
+assert.equal(sternBrocot(3), 5);
+```
+
+`sternBrocot(5)` should return `11`.
+
+```js
+assert.equal(sternBrocot(5), 11);
+```
+
+`sternBrocot(7)` should return `19`.
+
+```js
+assert.equal(sternBrocot(7), 19);
+```
+
+`sternBrocot(10)` should return `39`.
+
+```js
+assert.equal(sternBrocot(10), 39);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function sternBrocot(num) {
@@ -75,12 +91,7 @@ function sternBrocot(num) {
 }
 ```
 
-</div>
-</section>
-
-## Solution
-
-<section id='solution'>
+# --solutions--
 
 ```js
 function sternBrocot(num) {
@@ -100,5 +111,3 @@ function sternBrocot(num) {
   return n;
 }
 ```
-
-</section>