feat(curriculum): restore seed + solution to Chinese (#40683)

* feat(tools): add seed/solution restore script

* chore(curriculum): remove empty sections' markers

* chore(curriculum): add seed + solution to Chinese

* chore: remove old formatter

* fix: update getChallenges

parse translated challenges separately, without reference to the source

* chore(curriculum): add dashedName to English

* chore(curriculum): add dashedName to Chinese

* refactor: remove unused challenge property 'name'

* fix: relax dashedName requirement

* fix: stray tag

Remove stray `pre` tag from challenge file.

Signed-off-by: nhcarrigan <nhcarrigan@gmail.com>

Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>

curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-5-smallest-multiple.md

@@ -3,6 +3,7 @@ id: 5900f3711000cf542c50fe84
 title: 问题5：最小的倍数
 challengeType: 5
 videoUrl: ''
+dashedName: problem-5-smallest-multiple
 ---
 
 # --description--
@@ -41,5 +42,34 @@ assert.strictEqual(smallestMult(13), 360360);
 assert.strictEqual(smallestMult(20), 232792560);
 ```
 
+# --seed--
+
+## --seed-contents--
+
+```js
+function smallestMult(n) {
+
+  return true;
+}
+
+smallestMult(20);
+```
+
 # --solutions--
 
+```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;
+}
+```