chore: Port FreeSewing.dev to docusaurus

The replaces the NextJS site powering FreeSewing.dev with a Docusaurus
setup. It's part of my efforts to simplify FreeSewing's setup so we can
focus on our core value proposition.

sites/dev/docs/tutorials/pattern-design/part1/structure/readme.mdx

@@ -0,0 +1,32 @@
+---
+title: Folder structure
+order: 40
+---
+
+Inside the `freesewing` folder -- which might have a different name if that is
+the choice you made -- you will find a bunch of files and folders.
+
+The one that matter is the `design` folder. In it, you will find the following
+subfolders:
+
+- `from-bella`
+- `from-bent`
+- `from-breanna`
+- `from-brian`
+- `from-scratch`
+- `from-titan`
+- `tutorial`
+
+Remember when you click the **Design** icon in the header it would bring up
+this menu:
+
+![Design templates provided by the FreeSewing development environment](./templates.png)
+
+As you might have guessed by now, each of these options is contained in its
+own subfolder under `designs`. 
+
+You can edit the files under `designs/[template]/src/` and the changes you make
+will be reflected in the development environment.
+
+Don't take my word for it though. Let's start doing exactly that 
+in [Part 2](/tutorials/pattern-design/part2).