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/pattern/use/en.md

@@ -0,0 +1,19 @@
+---
+title: use()
+---
+
+```js
+Pattern pattern.use(object plugin)
+``` 
+Loads a freesewing plugin. This method is chainable.
+
+See [extending freesewing](/extend) for details about extending
+freesewing with plugins.
+
+<Fixme>
+
+ - Add code example
+ - Explain difference between run and build-time plugins
+
+</Fixme>
+