fix(challenge-md): Fix file names and preserve challenge order in meta.json

curriculum/challenges/en/08-coding-interview-prep/project-euler/problem-5-smallest-multiple.en.md

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+---
+id: 5900f3711000cf542c50fe84
+challengeType: 5
+title: 'Problem 5: Smallest multiple'
+---
+
+## Description
+<section id='description'>
+2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.
+What is the smallest positive number that is evenly divisible by all of the numbers from 1 to <code>n</code>?
+</section>
+
+## Instructions
+<section id='instructions'>
+
+</section>
+
+## Tests
+<section id='tests'>
+
+```yml
+- text: <code>smallestMult(5)</code> should return 60.
+  testString: 'assert.strictEqual(smallestMult(5), 60, ''<code>smallestMult(5)</code> should return 60.'');'
+- text: <code>smallestMult(7)</code> should return 420.
+  testString: 'assert.strictEqual(smallestMult(7), 420, ''<code>smallestMult(7)</code> should return 420.'');'
+- text: <code>smallestMult(10)</code> should return 2520.
+  testString: 'assert.strictEqual(smallestMult(10), 2520, ''<code>smallestMult(10)</code> should return 2520.'');'
+- text: <code>smallestMult(13)</code> should return 360360.
+  testString: 'assert.strictEqual(smallestMult(13), 360360, ''<code>smallestMult(13)</code> should return 360360.'');'
+- text: <code>smallestMult(20)</code> should return 232792560.
+  testString: 'assert.strictEqual(smallestMult(20), 232792560, ''<code>smallestMult(20)</code> should return 232792560.'');'
+
+```
+
+</section>
+
+## Challenge Seed
+<section id='challengeSeed'>
+
+<div id='js-seed'>
+
+```js
+function smallestMult(n) {
+  // Good luck!
+  return true;
+}
+
+smallestMult(20);
+```
+
+</div>
+
+
+
+</section>
+
+## Solution
+<section id='solution'>
+
+
+```js
+function smallestMult(n){
+  function gcd(a, b) {
+    return b === 0 ? a : gcd(b, a%b); // Euclidean algorithm
+  }
+
+  function lcm(a, b) {
+    return a * b / gcd(a, b);
+  }
+  var result = 1;
+  for(var i = 2; i <= n; i++) {
+    result = lcm(result, i);
+  }
+  return result;
+}
+```
+
+</section>