feat: Flat import of markdown repo

This is a flat (without history) import of (some of) the content
from our markdown module.

We've imported this without history because the repo contains our
blog posts and showcases posts content prior to porting them to strapi.

Since this contains many images, it would balloon the size of this repo
to import the full history.

Instead, please refer to the history of the (archived) markdown repo
at: https://github.com/freesewing/markdown

markdown/dev/reference/api/design/en.md

@@ -0,0 +1,38 @@
+---
+title: Design 
+order: 10
+---
+
+```js
+function freesewing.Design(
+  object config, 
+  object|array plugins, // optional
+  object|array conditionalPlugins // optional
+) 
+```
+
+A super-constructor to create a new pattern design. 
+It takes the following arguments:
+
+ - `config` : The pattern configuration
+ - `plugins` : Either a [plugin object](/guides/plugins/), or an array of plugin objects
+ - `conditionalPlugins` : Either a [conditional plugin object](/guides/plugins/conditionally-loading-build-time-plugins/), or an array 
+ of conditional plugin objects to (conditionally) load in your pattern
+
+```js
+import freesewing from "@freesewing/core"
+import plugins from "@freesewing/plugin-bundle"
+import config from "../config"
+
+// Create new design
+const Sorcha = new freesewing.Design(config, plugins)
+```
+
+<Tip>
+
+This method is a *super-constructor*. It will return a constructor 
+method that should be called to instantiate your pattern. 
+
+See [creating a new pattern design](/howtos/core/new-design/) for an example.
+
+</Tip>