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/getting-started-mac/node-versions/readme.mdx

@@ -0,0 +1,54 @@
+---
+title: Using a different Node.js version
+order: 30
+---
+
+Now that you've got Node.js setup, we can start setting up the FreeSewing
+development environment.
+
+But before doing so, let's look at how `nvm` can help you juggle different
+Node.js versions.
+
+### nvm ls
+
+To see the different Node.js versions on your system, run this command:
+
+```bash
+nvm ls
+```
+
+It will show you a list of local Node.js versions,
+either the version number or an _alias_ that points to a specific version.
+You should see the `lts/*` alias in the list which is what we've just installed.
+
+### nvm ls-remote
+
+To see all Node.js versions that are available, not just those you have locally,
+run this command:
+
+```bash
+nvm ls-remote
+```
+
+It will spit out a long list of Node.js versions that you can install.
+
+### nvm install
+
+For any of these versions, either local or remote, you can install them
+by making a note of the version or alias and running this command:
+
+```bash
+nvm install <version-or-alias>
+```
+
+### nvm use
+
+With multiple Node.js versions installed, `nvm` allows you to switch between different
+versions. Just tell it which version you want to use:
+
+```bash
+nvm use v10.22.1
+```
+
+If you picked a version that is not installed, `nvm` will simply tell you
+and even suggest the command you should type to install it. Handy!