[DOCS] Clarify the type of Azure storage for snapshots (#72826) (#72976)

Azure Storage accounts offer several storage services including Blob Storage, Table Storage, File Storage, and Storage Queues.  The intro page for this plugin should specify which type is used for elasticsearch snapshots.  This info is necessary for pricing at very least.

Co-authored-by: joshschmitter <45405518+joshschmitter@users.noreply.github.com>
Co-authored-by: Elastic Machine <elasticmachine@users.noreply.github.com>

docs/plugins/repository-azure.asciidoc

@@ -1,7 +1,7 @@
 [[repository-azure]]
 === Azure Repository Plugin
 
-The Azure Repository plugin adds support for using Azure as a repository for
+The Azure Repository plugin adds support for using https://docs.microsoft.com/en-us/azure/storage/blobs/storage-blobs-introduction[Azure Blob storage] as a repository for
 {ref}/modules-snapshots.html[Snapshot/Restore].
 
 :plugin_name: repository-azure