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/macros/en.md

@@ -0,0 +1,22 @@
+---
+title: Macros
+for: developers
+about: Complete list of all available macros and how to use them
+---
+
+Macros are a way to combine different operations into a single command,
+and are typically provided by plugins.
+
+Below is a list of available macros:
+
+<ReadMore list />
+
+<Note>All macros take a single object as their configuration. </Note>
+
+<Tip>
+
+For more info on a specific macro and examples, follow the link to the plugin that provides the macro.
+
+</Tip>
+
+