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/new-design/readme.mdx

@@ -0,0 +1,75 @@
+---
+title: Setting up the development environment
+order: 20
+---
+
+FreeSewing provides a development environment that visualizes your design for
+you. This tutorial is for the stand-alone development environment, not the
+monorepo development environment (which you may have set up if you followed a
+getting started tutorial).
+
+To set it up, I will open a terminal and enter the following command:
+
+```sh
+npx @freesewing/new-design
+```
+
+It will ask if it is ok to install the development environment in a new folder
+named `freesewing`. You can accept the default, or pick a different folder name
+if you prefer.
+
+It will also ask what package manager you would like to use. 
+Here too the default (`npm`) is fine., unless you are certain you have **yarn** installed.
+
+After answering these questions, files will be downloaded, dependencies installed,
+and it will also initialize a git repository for you (if you have git on your system).
+
+:::note
+
+This will take a few minutes because the development environment has a number
+of dependencies that need to be downloaded.
+
+:::
+
+When it's ready, you can enter the `freesewing` directory that was just created and run `npm run dev`:
+
+```sh
+cd freesewing
+npm run dev
+```
+
+Or if you want to use yarn as package manager:
+
+```sh
+cd freesewing
+yarn dev
+```
+
+Now open a browser and go to http://localhost:8000
+
+If all goes well, we'll should see this landing page:
+
+![The FreeSewing development environment](./nd.png)
+
+:::tip
+
+##### More detailed setup tutorials are available
+
+This pattern design tutorial contains only an abbreviated overview
+of the setup process.
+For more detailed instructions, please refer to one of our setup tutorials:
+
+- [Getting started on Linux](/tutorials/getting-started-linux)
+- [Getting started on Mac](/tutorials/getting-started-mac)
+- [Getting started on Windows](/tutorials/getting-started-windows)
+
+:::
+
+:::tip
+
+##### Need help?
+
+If you run into any issues, head over to [FreeSewing.org/support](https://next.freesewing.org/support)
+which lists the various ways in which you can get help.
+
+:::