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/en.md

@@ -0,0 +1,33 @@
+---
+title: Core API
+for: developers
+icons: 
+  - javascript
+  - terms
+about: FreeSewing's core API reference documents all available methods and objects
+---
+
+```js
+import freesewing from '@freesewing/core'
+```
+
+The `@freesewing/core` default export is a single object with the following properties:
+
+ - `version`: A string containing the FreeSewing version number
+ - `Design()`: A *super-constructor* to create new pattern designs.
+ - `Pattern()`: The `Pattern` constructor
+ - `Point()`: The `Point` constructor
+ - `Path()`: The `Path` constructor
+ - `Snippet()`: The `Snippet` constructor
+ - `utils`: A collection of utilities
+ - `patterns`: FIXME: Explain use-case
+ - `plugins`: FIXME: Explain use-case
+
+<Tip>
+
+You will typically only use the `Design()` super-constructor.
+
+The other constructors and utilities are exported to facilitate unit testing.  
+
+</Tip>
+