Fix code sample for edit document by filter route (#3082)

Author: irevoire

reference/api/documents.mdx

@@ -439,7 +439,7 @@ Use `context` to pass data to the `function` scope. By default a function only h
 
 ```sh
 curl \
--X POST 'http://localhost:7700/indexes/INDEX_NAME/search' \
+-X POST 'http://localhost:7700/indexes/INDEX_NAME/documents/edit' \
 -H 'Content-Type: application/json' \
 --data-binary '{
   "function": "doc.title = `${doc.title.to_upper()}`"