Docs: fix index

Signed-off-by: Solomon Hykes <solomon@dagger.io>

docs/introduction/index.md

@@ -0,0 +1,13 @@
+---
+slug: /
+displayed_sidebar: '0.2'
+---
+
+# Dagger Documentation
+
+```mdx-code-block
+import DocCardList from '@theme/DocCardList';
+import {useCurrentSidebarCategory} from '@docusaurus/theme-common';
+
+<DocCardList items={useCurrentSidebarCategory().items}/>
+```