fix(guide): restructure curriculum guide articles (#36501)

* fix: restructure certifications guide articles
* fix: added 3 dashes line before prob expl
* fix: added 3 dashes line before hints
* fix: added 3 dashes line before solutions

guide/english/certifications/coding-interview-prep/project-euler/problem-10-summation-of-primes/index.md

@@ -1,15 +1,20 @@
 ---
 title: Summation of primes
 ---
-## Problem 10: Summation of primes
+# Problem 10: Summation of primes
 
-### Method:
+---
+## Problem Explanation
 - In this challenge we need to find sum of all prime numbers up to `n`.
 - Example:
   - If `n = 10` then prime numbers before it are `2, 3, 5, 7` and their sum is `17`.
 - We've used Sieve of Eratosthenes algorithm to find prime numbers in the below solution.
 
-### Solution:
+
+---
+## Solutions
+<details><summary>Solution 1 (Click to Show/Hide)</summary>
+
 ```js
 function primeSummation(n) {
   
@@ -50,5 +55,6 @@ function primeSummation(n) {
 ```
 
 
-### References:
+#### Relevant Links
 - Sieve of Eratosthenes [Wikipedia](https://en.wikipedia.org/wiki/Sieve_of_Eratosthenes)
+</details>