feat: Add various content types to docusaurus (#7231)

This brings blog posts, showcase posts, and newsletter editions into the Docusaurus site.

It also adds support for using TailwindCSS inside a container. So this will probably end up being the new freesewing.org site in v4.

sites/dev/docs/tutorials/getting-started-linux/dev-setup/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Setting up the FreeSewing development environment
-order: 40
+sidebar_position: 40
 ---
 
 FreeSewing provides a development environment to help you design and develop

sites/dev/docs/tutorials/getting-started-linux/dev-start/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Start the development environment
-order: 50
+sidebar_position: 50
 ---
 
 FreeSewing provides a development environment to help you design and develop patterns.
@@ -21,7 +21,9 @@ yarn lab
 Then point your browser to http://localhost:8000
 
 :::tip
+
 ### Adding a new design
+
 This is all you need to work on existing designs. If you'd like to add a new design, run:
 
 ```bash

sites/dev/docs/tutorials/getting-started-linux/installing-node/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Installing Node.js
-order: 20
+sidebar_position: 20
 ---
 
 Now we will use `nvm` to install Node.js. Run the following command:

sites/dev/docs/tutorials/getting-started-linux/installing-nvm/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Installing nvm
-order: 10
+sidebar_position: 10
 ---
 
 FreeSewing is built with [Node.js](https://nodejs.org/), a JavaScript runtime.

sites/dev/docs/tutorials/getting-started-linux/node-versions/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Using a different Node.js version
-order: 30
+sidebar_position: 30
 ---
 
 Now that you've got Node.js setup, we can start setting up the FreeSewing

sites/dev/docs/tutorials/getting-started-linux/readme.mdx

@@ -1,6 +1,6 @@
 ---
 title: Getting started on Linux
-order: 15
+sidebar_position: 15
 ---
 
 In this tutorial, we will setup Node.js and initialize the FreeSewing