Update README.md

Author: uttamukkoji

README.md

@@ -117,7 +117,7 @@ Contentstack provides a GraphQL playground, which is a GraphiQL interface, to te
 
 Open a browser of your choice and hit the URL given below:
 ```
-https://www.contentstack.com/docs/apis/graphql-content-delivery-api/explorer/
+https://www.contentstack.com/docs/developers/apis/graphql-content-delivery-api/explorer/
 ```
 
 **Note**: If you have pieces of data you may want to reuse in multiple places, make use of fragments. Refer the [Using fragments](https://www.apollographql.com/docs/ios/fragments.html) doc for more details.