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/hooks/en.md

@@ -0,0 +1,17 @@
+---
+title: Hooks API
+for: developers
+about: Documents the available lifecycle hooks in Core and how to use them
+---
+
+A **hook** is a lifecycle event.
+
+You can register a method for a hook. When the hook is triggered, your method will be
+called. It will receive two parameters:
+
+ - An object relevant to the hook (see the specific hook for details)
+ - Data passed when the hook was registered (optional)
+
+Below is a list of all available hooks:
+
+<ReadMore list />