Feat: add new Markdown parser (#39800)

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

curriculum/challenges/english/10-coding-interview-prep/rosetta-code/long-multiplication.md

@@ -5,45 +5,80 @@ challengeType: 5
 forumTopicId: 385269
 ---
 
-## Description
-<section id='description'>
-Explicitly implement  <a href="https://en.wikipedia.org/wiki/long multiplication">long multiplication</a>.
+# --description--
+
+Explicitly implement [long multiplication](<https://en.wikipedia.org/wiki/long multiplication>).
+
 This is one possible approach to arbitrary-precision integer algebra.
-</section>
 
-## Instructions
-<section id='instructions'>
+# --instructions--
+
 Write a function that takes two strings of large numbers as parameters. Your function should return the product of these two large numbers as a string.
-<strong>Note:</strong> In JavaScript, arithmetic operations are inaccurate with large numbers, so you will have to implement precise multiplication yourself.
-</section>
 
-## Tests
-<section id='tests'>
+**Note:** In JavaScript, arithmetic operations are inaccurate with large numbers, so you will have to implement precise multiplication yourself.
 
-``` yml
-tests:
-  - text: <code>mult</code> should be a function.
-    testString: assert(typeof mult == 'function');
-  - text: <code>mult("18446744073709551616", "18446744073709551616")</code> should return a string.
-    testString: assert(typeof mult("18446744073709551616", "18446744073709551616") == 'string');
-  - text: <code>mult("18446744073709551616", "18446744073709551616")</code> should return <code>"340282366920938463463374607431768211456"</code>.
-    testString: assert.equal(mult("18446744073709551616", "18446744073709551616"), "340282366920938463463374607431768211456");
-  - text: <code>mult("31844674073709551616", "1844674407309551616")</code> should return <code>"58743055272886011737990786529368211456"</code>.
-    testString: assert.equal(mult("31844674073709551616", "1844674407309551616"), "58743055272886011737990786529368211456");
-  - text: <code>mult("1846744073709551616", "44844644073709551616")</code> should return <code>"82816580680737279241781007431768211456"</code>.
-    testString: assert.equal(mult("1846744073709551616", "44844644073709551616"), "82816580680737279241781007431768211456");
-  - text: <code>mult("1844674407370951616", "1844674407709551616")</code> should return <code>"3402823669833978308014392742590611456"</code>.
-    testString: assert.equal(mult("1844674407370951616", "1844674407709551616"), "3402823669833978308014392742590611456");
-  - text: <code>mult("2844674407370951616", "1844674407370955616")</code> should return <code>"5247498076580334548376218009219475456"</code>.
-    testString: assert.equal(mult("2844674407370951616", "1844674407370955616"), "5247498076580334548376218009219475456");
+# --hints--
+
+`mult` should be a function.
+
+```js
+assert(typeof mult == 'function');
 ```
 
-</section>
+`mult("18446744073709551616", "18446744073709551616")` should return a string.
 
-## Challenge Seed
-<section id='challengeSeed'>
+```js
+assert(typeof mult('18446744073709551616', '18446744073709551616') == 'string');
+```
 
-<div id='js-seed'>
+`mult("18446744073709551616", "18446744073709551616")` should return `"340282366920938463463374607431768211456"`.
+
+```js
+assert.equal(
+  mult('18446744073709551616', '18446744073709551616'),
+  '340282366920938463463374607431768211456'
+);
+```
+
+`mult("31844674073709551616", "1844674407309551616")` should return `"58743055272886011737990786529368211456"`.
+
+```js
+assert.equal(
+  mult('31844674073709551616', '1844674407309551616'),
+  '58743055272886011737990786529368211456'
+);
+```
+
+`mult("1846744073709551616", "44844644073709551616")` should return `"82816580680737279241781007431768211456"`.
+
+```js
+assert.equal(
+  mult('1846744073709551616', '44844644073709551616'),
+  '82816580680737279241781007431768211456'
+);
+```
+
+`mult("1844674407370951616", "1844674407709551616")` should return `"3402823669833978308014392742590611456"`.
+
+```js
+assert.equal(
+  mult('1844674407370951616', '1844674407709551616'),
+  '3402823669833978308014392742590611456'
+);
+```
+
+`mult("2844674407370951616", "1844674407370955616")` should return `"5247498076580334548376218009219475456"`.
+
+```js
+assert.equal(
+  mult('2844674407370951616', '1844674407370955616'),
+  '5247498076580334548376218009219475456'
+);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function mult(strNum1, strNum2) {
@@ -51,12 +86,7 @@ function mult(strNum1, strNum2) {
 }
 ```
 
-</div>
-
-</section>
-
-## Solution
-<section id='solution'>
+# --solutions--
 
 ```js
 function mult(strNum1, strNum2) {
@@ -78,5 +108,3 @@ function mult(strNum1, strNum2) {
     return aResult.reverse().join("");
 }
 ```
-
-</section>