docs: add haystack tile to AI integrations, replace Apify Store screenshot (#1308)

Added haystack tile to AI integrations. 
Also replaced Apify Store screenshot with a new one.

Author: jirispilka

sources/platform/integrations/images/apify-store.png

@@ -155,6 +155,12 @@ If you are working on an AI/LLM-related project, we recommend you look into the
         imageUrl="/img/platform/integrations/llamaindex.jpeg"
         smallImage
     />
+    <Card
+        title="Haystack"
+        to="./integrations/haystack"
+        imageUrl="/img/platform/integrations/haystack.png"
+        smallImage
+    />
     <Card
         title="Flowise"
         to="./integrations/flowise"