Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/look-and-say-sequence.md

@@ -5,52 +5,74 @@ challengeType: 5
 forumTopicId: 385277
 ---
 
-## Description
-<section id='description'>
-The <a href="https://en.wikipedia.org/wiki/Look and say sequence" target="_blank">Look and say sequence</a> is a recursively defined sequence of numbers.
+# --description--
+
+The [Look and say sequence](<https://en.wikipedia.org/wiki/Look and say sequence>) is a recursively defined sequence of numbers.
+
 Sequence Definition
+
 <ul><li>Take a decimal number</li>
 <li><span>Look</span> at the number, visually grouping consecutive runs of the same digit.</li>
 <li><span>Say</span> the number, from left to right, group by group; as how many of that digit there are - followed by the digit grouped.</li></ul><span> This becomes the next number of the sequence.</span>
-<span>An example:</span>
+
+An example:
+
 <ul><li>Starting with the number 1, you have <span>one</span> 1 which produces 11</li>
 <li>Starting with 11, you have <span>two</span> 1's. I.E.: 21</li>
 <li>Starting with 21, you have <span>one</span> 2, then <span>one</span> 1. I.E.: (12)(11) which becomes 1211</li>
 <li>Starting with 1211, you have <span>one</span> 1, <span>one</span> 2, then <span>two</span> 1's. I.E.: (11)(12)(21) which becomes 111221</li></ul>
-</section>
 
-## Instructions
-<section id='instructions'>
+# --instructions--
+
 Write a function that accepts a string as a parameter, processes it, and returns the resultant string.
-</section>
 
-## Tests
-<section id='tests'>
+# --hints--
 
-``` yml
-tests:
-  - text: <code>lookAndSay</code> should be a function.
-    testString: assert(typeof lookAndSay == 'function');
-  - text: <code>lookAndSay("1")</code> should return a string.
-    testString: assert(typeof lookAndSay("1") == 'string');
-  - text: <code>lookAndSay("1")</code> should return <code>"11"</code>.
-    testString: assert.equal(lookAndSay("1"), "11");
-  - text: <code>lookAndSay("11")</code> should return <code>"21"</code>.
-    testString: assert.equal(lookAndSay("11"), "21");
-  - text: <code>lookAndSay("21")</code> should return <code>"1211"</code>.
-    testString: assert.equal(lookAndSay("21"), "1211");
-  - text: <code>lookAndSay("1211")</code> should return <code>"111221"</code>.
-    testString: assert.equal(lookAndSay("1211"), "111221");
-  - text: <code>lookAndSay("3542")</code> should return <code>"13151412"</code>.
-    testString: assert.equal(lookAndSay("3542"), "13151412");
+`lookAndSay` should be a function.
+
+```js
+assert(typeof lookAndSay == 'function');
 ```
 
-</section>
+`lookAndSay("1")` should return a string.
 
-## Challenge Seed
-<section id='challengeSeed'>
+```js
+assert(typeof lookAndSay('1') == 'string');
+```
 
-<div id='js-seed'>
+`lookAndSay("1")` should return `"11"`.
+
+```js
+assert.equal(lookAndSay('1'), '11');
+```
+
+`lookAndSay("11")` should return `"21"`.
+
+```js
+assert.equal(lookAndSay('11'), '21');
+```
+
+`lookAndSay("21")` should return `"1211"`.
+
+```js
+assert.equal(lookAndSay('21'), '1211');
+```
+
+`lookAndSay("1211")` should return `"111221"`.
+
+```js
+assert.equal(lookAndSay('1211'), '111221');
+```
+
+`lookAndSay("3542")` should return `"13151412"`.
+
+```js
+assert.equal(lookAndSay('3542'), '13151412');
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function lookAndSay(str) {
@@ -58,12 +80,7 @@ function lookAndSay(str) {
 }
 ```
 
-</div>
-
-</section>
-
-## Solution
-<section id='solution'>
+# --solutions--
 
 ```js
 function lookAndSay(str) {
@@ -72,5 +89,3 @@ function lookAndSay(str) {
     });
 }
 ```
-
-</section>