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/create-grids-within-grids/index.md

@@ -1,20 +1,24 @@
 ---
 title: Create Grids within Grids
 ---
-## Create Grids within Grids
+# Create Grids within Grids
 
+---
+## Problem Explanation
 A grid within a grid is made the same as any other grid.
 1. Just nest one element inside another,
 2. set them *both* to grids,
 3. and *POOF*! You have a grid-within-a-grid.
 
-### Nesting an element
+**Nesting an element**
+
 For any refreshers, nesting an element looks like this:
 `<div class='gridElement'> Here is your grid
   <div class='nestedGridElement'>Here is your nested grid</div>
  </div>`
 
-### Setting your elements to grids
+**Setting your elements to grids**
+
 After that, adjust the following CSS properties:
 `.gridElement{
   /* this gives you a grid */
@@ -26,6 +30,6 @@ After that, adjust the following CSS properties:
     display: grid;
  }`
 
-### Additional Information
+** Notes:**
 After that, feel free to customize your grids however you like.
 i.e. `grid-template-columns: auto 1fr;` might look good in that nested grid.