Feat/add guide for writing solutions (#35041)

* feat: add guide for writing challenge solution

* feat: fix markdown for solution example

* fix: add requested changes for formatting solution

docs/style-guide-for-curriculum-challenges.md

@@ -18,6 +18,7 @@ With that practical focus in mind, let’s talk about the requirements for our c
 - [Writing instructions](#writing-instructions)
 - [Formatting challenge text](#formatting-challenge-text)
 - [Formatting seed code](#formatting-seed-code)
+- [Formatting solution](#formatting-solution)
 - [Why do we have all these rules?](#why-do-we-have-all-these-rules)
 
 ## Proper nouns
@@ -139,6 +140,40 @@ Here are specific formatting guidelines for the challenge seed code:
 
     `// Fix this line`
 
+## Formatting Solution
+
+The challenge solution must be in proper markdown tags. The code must be wrapped in `section` tags with an id of `solution`.
+
+```
+<section id='solution'>
+
+three backticks + html or js
+ [ SOLUTION CODE]
+three backticks
+
+</section>
+```
+
+Example:
+
+````
+<section id='solution'>
+  
+```html
+<style>
+  #container p {
+    font-family: Arial, sans-serif;
+  }
+</style>
+
+<div id="container">
+  <p>Hello World!</p>
+</div>
+```
+
+</section>
+````
+
 ## Why do we have all these rules?
 
 Our goal is to develop a fun and clear interactive learning experience.