Creates Frontend Style guide

What does this MR do?

• Follows same structure as UX guide, divides each section into a new file. This allows us to work simultaneity in different parts of the the style guide and makes it easier to add documentation. It keeps the same sections.
• Adds Style Guide for Vue components
• Adds Common missing Rules for JavaScript and SCSS
• Adds a guide for when to use and not use Vue.js

Why was this MR needed?

We need a style guide.

What are the relevant issue numbers?

Closes #28713 (closed)