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/responsive-web-design/css-grid/add-columns-with-grid-template-columns/index.md

@@ -1,24 +1,36 @@
 ---
 title: Add Columns with grid-template-columns
 ---
-## Add Columns with grid-template-columns
+# Add Columns with grid-template-columns
 
+---
+## Problem Explanation
 In this challenge, you are required to define columns for the grid.
 
-### Hint
+
+---
+## Hints
+
+### Hint 1
 
 You can define columns by declaring the following in your CSS codeblock:
 
-````css
+```css
 grid-template-columns: parameters;
-````
+```
 
 where parameters is whatever you want it to be.
 
-### Solution
+
+---
+## Solutions
+
+<details><summary>Solution 1 (Click to Show/Hide)</summary>
 
 Since the challenge requires you to create three columns of 100px each, declare the following in your .container CSS codeblock:
 
-````css
+```css
 grid-template-columns: 100px 100px 100px;
-````
+```
+
+</details>