Updated Articles Pages (#1329)

* Updated Articles Pages

* fixes

* Links removed

* Fixed url

* light theme fix

* toc fix

* new article categories

* categorize articles

* fix article preview images

* rename categories

---------

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

qdrant-landing/content/headless/docs-header.md

@@ -16,9 +16,9 @@ menuItems:
   - id: menu-2
     name: Build
     url: /documentation/build/
-#  - id: menu-3
-#    name: Learn
-#    url: /documentation/learn/
+  - id: menu-3
+    name: Learn
+    url: /articles/
   - id: menu-4
     name: API Reference
     url: https://api.qdrant.tech/api-reference