Add exp banner

Author: MaedahBatool

docs/admin/config/batch_changes.mdx

@@ -344,6 +344,8 @@ However, if the user deletion is permanent, deleting both account and data, then
 
 ## Batch Spec Library
 
+<Callout type="note"> Batch Spec Library is currently in Experimental.</Callout>
+
 The Batch Spec Library is a collection of Batch Specs that can be used to create Batch Changes. Sourcegraph provides a few Batch Specs out of the box.
 
 Site admins can manage the library through the GraphQL mutations `createBatchSpecLibraryRecord`, `updateBatchSpecLibraryRecord`, and `deleteBatchSpecLibraryRecord`. Use the query `batchSpecLibrary` to list all available Batch Spec examples.