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/snippets/buttonhole/en.md

@@ -0,0 +1,25 @@
+---
+title: buttonhole
+---
+
+The `buttonhole` snippet is used to mark buttonhole placement and is
+provided by [plugin-buttons](/reference/plugins/buttons/).
+
+```js
+snippets.demo = new Snippet('buttonhole', points.anchor)
+```
+
+<Example part="snippets_buttonhole" caption="An example of the buttonhole snippet" />
+
+<Note>
+
+##### Aligning your buttons and buttonholes
+
+We provide three buttonhole snippets with a different alignment:
+
+ - [buttonhole](/reference/snippets/buttonhole/): Anchor point is the middle of the buttonhole
+ - [buttonhole-start](/reference/snippets/buttonhole-start/): Anchor point is the start of the buttonhole
+ - [buttonhole-end](/reference/snippets/buttonhole-end/): Anchor point is the end of the buttonhole
+
+</Note>
+