Add Course page (#1844)

* Add Course page

* Added shortcodes and buttons to navigate to the next page

* move course images from layout

* decouple documentation and course layout

* decouple course sidebar

* move accordion js handlers into global unconditional js

* enable search on courses

* allow nested courses

* disable links for now

---------

Co-authored-by: generall <andrey@vasnetsov.com>

qdrant-landing/themes/qdrant-2024/layouts/course/single.html

@@ -0,0 +1,11 @@
+<!doctype html>
+<html lang="en">
+  {{- partial "head.html" . -}}
+  <body>
+    <main>
+      {{ partial "documentation/header" . }}
+      {{ partial "course/content-layout" . }}
+    </main>
+  </body>
+  {{ partial "js.html" . }}
+</html>