Feat: add new Markdown parser (#39800)

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

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

@@ -1,51 +1,67 @@
 ---
-title: Entropy
 id: 599d15309e88c813a40baf58
+title: Entropy
 challengeType: 5
 forumTopicId: 302254
 ---
 
-## Description
-<section id='description'>
+# --description--
+
 Calculate the Shannon entropy H of a given input string.
+
 Given the discreet random variable $X$ that is a string of $N$ "symbols" (total characters) consisting of $n$ different characters (n=2 for binary), the Shannon entropy of X in bits/symbol is:
-$H_2(X) = -\sum_{i=1}^n \frac{count_i}{N} \log_2 \left(\frac{count_i}{N}\right)$
+
+$H_2(X) = -\\sum\_{i=1}^n \\frac{count_i}{N} \\log_2 \\left(\\frac{count_i}{N}\\right)$
+
 where $count_i$ is the count of character $n_i$.
-</section>
 
-## Instructions
-<section id='instructions'>
+# --hints--
 
-</section>
-
-## Tests
-<section id='tests'>
-
-```yml
-tests:
-  - text: <code>entropy</code> should be a function.
-    testString: assert(typeof entropy === 'function');
-  - text: <code>entropy("0")</code> should return <code>0</code>
-    testString: assert.equal(entropy('0'), 0);
-  - text: <code>entropy("01")</code> should return <code>1</code>
-    testString: assert.equal(entropy('01'), 1);
-  - text: <code>entropy("0123")</code> should return <code>2</code>
-    testString: assert.equal(entropy('0123'), 2);
-  - text: <code>entropy("01234567")</code> should return <code>3</code>
-    testString: assert.equal(entropy('01234567'), 3);
-  - text: <code>entropy("0123456789abcdef")</code> should return <code>4</code>
-    testString: assert.equal(entropy('0123456789abcdef'), 4);
-  - text: <code>entropy("1223334444")</code> should return <code>1.8464393446710154</code>
-    testString: assert.equal(entropy('1223334444'), 1.8464393446710154);
+`entropy` should be a function.
 
+```js
+assert(typeof entropy === 'function');
 ```
 
-</section>
+`entropy("0")` should return `0`
 
-## Challenge Seed
-<section id='challengeSeed'>
+```js
+assert.equal(entropy('0'), 0);
+```
 
-<div id='js-seed'>
+`entropy("01")` should return `1`
+
+```js
+assert.equal(entropy('01'), 1);
+```
+
+`entropy("0123")` should return `2`
+
+```js
+assert.equal(entropy('0123'), 2);
+```
+
+`entropy("01234567")` should return `3`
+
+```js
+assert.equal(entropy('01234567'), 3);
+```
+
+`entropy("0123456789abcdef")` should return `4`
+
+```js
+assert.equal(entropy('0123456789abcdef'), 4);
+```
+
+`entropy("1223334444")` should return `1.8464393446710154`
+
+```js
+assert.equal(entropy('1223334444'), 1.8464393446710154);
+```
+
+# --seed--
+
+## --seed-contents--
 
 ```js
 function entropy(s) {
@@ -53,19 +69,11 @@ function entropy(s) {
 }
 ```
 
-</div>
-
-
-
-</section>
-
-## Solution
-<section id='solution'>
-
+# --solutions--
 
 ```js
 function entropy(s) {
-	// Create a dictionary of character frequencies and iterate over it.
+    // Create a dictionary of character frequencies and iterate over it.
   function process(s, evaluator) {
     let h = Object.create(null),
       k;
@@ -74,7 +82,7 @@ function entropy(s) {
     if (evaluator) for (k in h) evaluator(k, h[k]);
     return h;
   }
-	// Measure the entropy of a string in bits per symbol.
+    // Measure the entropy of a string in bits per symbol.
 
   let sum = 0,
     len = s.length;
@@ -84,7 +92,4 @@ function entropy(s) {
   });
   return sum;
 }
-
 ```
-
-</section>