Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/lychrel-numbers.md

@@ -5,8 +5,8 @@ challengeType: 5
 forumTopicId: 385287
 ---
 
-## Description
-<section id='description'>
+# --description--
+
 <ol>
   <li>Take an integer <code>n₀</code>, greater than zero.</li>
   <li>Form the next number <code>n</code> of the series by reversing <code>n₀</code> and adding it to <code>n₀</code></li>
@@ -30,17 +30,17 @@ And if `n₀` = 55 we get:
 110 + 011 = 121,  a palindrome!
 ```
 
-Notice that the check for a palindrome happens <i>after</i> an addition.
+Notice that the check for a palindrome happens *after* an addition.
 
-Some starting numbers seem to go on forever; the recurrence relation for 196 has been calculated for millions of repetitions forming numbers with millions of digits, without forming a palindrome. These numbers that do not end in a palindrome are called <b>Lychrel numbers</b>.
+Some starting numbers seem to go on forever; the recurrence relation for 196 has been calculated for millions of repetitions forming numbers with millions of digits, without forming a palindrome. These numbers that do not end in a palindrome are called **Lychrel numbers**.
 
 For the purposes of this task a Lychrel number is any starting number that does not form a palindrome within 500 (or more) iterations.
 
-<strong>Seed and related Lychrel numbers:</strong>
+**Seed and related Lychrel numbers:**
 
 Any integer produced in the sequence of a Lychrel number is also a Lychrel number.
 
-In general, any sequence from one Lychrel number <i>might</i> converge to join the sequence from a prior Lychrel number candidate; for example the sequences for the numbers 196 and then 689 begin:
+In general, any sequence from one Lychrel number *might* converge to join the sequence from a prior Lychrel number candidate; for example the sequences for the numbers 196 and then 689 begin:
 
 ```bash
     196
@@ -59,47 +59,65 @@ In general, any sequence from one Lychrel number <i>might</i> converge to join t
 
 So we see that the sequence starting with 689 converges to, and continues with the same numbers as that for 196.
 
-Because of this we can further split the Lychrel numbers into true <b>Seed</b> Lychrel number candidates, and <b>Related</b> numbers that produce no palindromes but have integers in their sequence seen as part of the sequence generated from a lower Lychrel number.
+Because of this we can further split the Lychrel numbers into true **Seed** Lychrel number candidates, and **Related** numbers that produce no palindromes but have integers in their sequence seen as part of the sequence generated from a lower Lychrel number.
 
-</section>
+# --instructions--
 
-## Instructions
-
-<section id='instructions'>
 Write a function that takes a number as a parameter. Return true if the number is a Lynchrel number. Otherwise, return false. Remember that the iteration limit is 500.
-</section>
 
-## Tests
+# --hints--
 
-<section id='tests'>
+`isLychrel` should be a function.
 
-```yml
-tests:
-  - text: <code>isLychrel</code> should be a function.
-    testString: assert(typeof isLychrel === 'function');
-  - text: <code>isLychrel(12)</code> should return a boolean.
-    testString: assert(typeof isLychrel(12) === 'boolean');
-  - text: <code>isLychrel(12)</code> should return <code>false</code>.
-    testString: assert.equal(isLychrel(12), false);
-  - text: <code>isLychrel(55)</code> should return <code>false</code>.
-    testString: assert.equal(isLychrel(55), false);
-  - text: <code>isLychrel(196)</code> should return <code>true</code>.
-    testString: assert.equal(isLychrel(196), true);
-  - text: <code>isLychrel(879)</code> should return <code>true</code>.
-    testString: assert.equal(isLychrel(879), true);
-  - text: <code>isLychrel(44987)</code> should return <code>false</code>.
-    testString: assert.equal(isLychrel(44987), false);
-  - text: <code>isLychrel(7059)</code> should return <code>true</code>.
-    testString: assert.equal(isLychrel(7059), true);
+```js
+assert(typeof isLychrel === 'function');
 ```
 
-</section>
+`isLychrel(12)` should return a boolean.
 
-## Challenge Seed
+```js
+assert(typeof isLychrel(12) === 'boolean');
+```
 
-<section id='challengeSeed'>
+`isLychrel(12)` should return `false`.
 
-<div id='js-seed'>
+```js
+assert.equal(isLychrel(12), false);
+```
+
+`isLychrel(55)` should return `false`.
+
+```js
+assert.equal(isLychrel(55), false);
+```
+
+`isLychrel(196)` should return `true`.
+
+```js
+assert.equal(isLychrel(196), true);
+```
+
+`isLychrel(879)` should return `true`.
+
+```js
+assert.equal(isLychrel(879), true);
+```
+
+`isLychrel(44987)` should return `false`.
+
+```js
+assert.equal(isLychrel(44987), false);
+```
+
+`isLychrel(7059)` should return `true`.
+
+```js
+assert.equal(isLychrel(7059), true);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function isLychrel(n) {
@@ -107,13 +125,7 @@ function isLychrel(n) {
 }
 ```
 
-</div>
-
-</section>
-
-## Solution
-
-<section id='solution'>
+# --solutions--
 
 ```js
 function isLychrel(n) {
@@ -136,5 +148,3 @@ function isLychrel(n) {
   return i == 500;
 }
 ```
-
-</section>