Add AI search location to fern documentation

Add AI search configuration to documentation.

Author: sahil485

fern/docs.yml

@@ -10,6 +10,10 @@ instances:
 
 title: Fern Documentation
 
+ai-search:
+  location:
+    - docs
+
 metadata:
   og:image: https://fern-docs.s3.us-east-2.amazonaws.com/fern-docs-og_image-compressed.png
   twitter:image: https://fern-docs.s3.us-east-2.amazonaws.com/fern-docs-og_image-compressed.png