Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-29-distinct-powers.md

@@ -1,12 +1,11 @@
 ---
 id: 5900f3891000cf542c50fe9c
-challengeType: 5
 title: 'Problem 29: Distinct powers'
+challengeType: 5
 forumTopicId: 301941
 ---
 
-## Description
-<section id='description'>
+# --description--
 
 Consider all integer combinations of ab for 2 ≤ a ≤ 5 and 2 ≤ b ≤ 5:
 
@@ -23,39 +22,43 @@ If they are then placed in numerical order, with any repeats removed, we get the
   4, 8, 9, 16, 25, 27, 32, 64, 81, 125, 243, 256, 625, 1024, 3125
 </div>
 
-How many distinct terms are in the sequence generated by <var>a<sup>b</sup></var> for 2 ≤ <var>a</var> ≤ <var>`n`</var> and 2 ≤ <var>b</var> ≤ <var>`n`</var>?
+How many distinct terms are in the sequence generated by `ab` for 2 ≤ `a` ≤ `n` and 2 ≤ `b` ≤ `n`?
 
-</section>
+# --hints--
 
-## Instructions
-<section id='instructions'>
-
-</section>
-
-## Tests
-<section id='tests'>
-
-```yml
-tests:
-  - text: <code>distinctPowers(15)</code> should return a number.
-    testString: assert(typeof distinctPowers(15) === 'number');
-  - text: <code>distinctPowers(15)</code> should return 177.
-    testString: assert.strictEqual(distinctPowers(15), 177);
-  - text: <code>distinctPowers(20)</code> should return 324.
-    testString: assert.strictEqual(distinctPowers(20), 324);
-  - text: <code>distinctPowers(25)</code> should return 519.
-    testString: assert.strictEqual(distinctPowers(25), 519);
-  - text: <code>distinctPowers(30)</code> should return 755.
-    testString: assert.strictEqual(distinctPowers(30), 755);
+`distinctPowers(15)` should return a number.
 
+```js
+assert(typeof distinctPowers(15) === 'number');
 ```
 
-</section>
+`distinctPowers(15)` should return 177.
 
-## Challenge Seed
-<section id='challengeSeed'>
+```js
+assert.strictEqual(distinctPowers(15), 177);
+```
 
-<div id='js-seed'>
+`distinctPowers(20)` should return 324.
+
+```js
+assert.strictEqual(distinctPowers(20), 324);
+```
+
+`distinctPowers(25)` should return 519.
+
+```js
+assert.strictEqual(distinctPowers(25), 519);
+```
+
+`distinctPowers(30)` should return 755.
+
+```js
+assert.strictEqual(distinctPowers(30), 755);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function distinctPowers(n) {
@@ -66,15 +69,7 @@ function distinctPowers(n) {
 distinctPowers(30);
 ```
 
-</div>
-
-
-
-</section>
-
-## Solution
-<section id='solution'>
-
+# --solutions--
 
 ```js
 const distinctPowers = (n) => {
@@ -88,5 +83,3 @@ const distinctPowers = (n) => {
   return list.length;
 };
 ```
-
-</section>