adding case studdy about squarespace

[CecilieMari]

Adding CA development platforms

[jaaneh]

@CecilieMari
Please can you fix the frontmatter at the very top of your files? The current frontmatter you have is invalid due to capitalized names. I.e Title vs title, etc.

You can replace it with this:

---
title: Squarespace Case Study
author: Cecilie Mari Monsen <CecilieMari>
tags: Squarespace, web, webpage builder
---

• Undo any changes done to the example case study file. Only changes should be the file you add.
• There's also some conflicts that need to be resolved.

Once you've sorted this out I can merge your PR :)