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/editors/howtos/blogpost/add-body/en.md

@@ -0,0 +1,13 @@
+---
+title: Add the body of the blog post
+order: 90
+---
+
+Below the frontmatter, you can write the body of your blog post, [using markdown](/editors/markdown/).
+
+
+<Tip>
+
+You can look at [one of the many blog posts](https://github.com/freesewing/markdown/tree/develop/org/blog) for examples.
+
+</Tip>