Merge pull request rails#42548 from ceritium/active-storage-guide-minio-example

[ci skip] Add link with full list of options for S3-compatible services

Author: guilleiguaran

guides/source/active_storage_overview.md

@@ -185,6 +185,8 @@ digitalocean:
   # ...and other options
 ```
 
+There are many other options available. You can check them in [AWS S3 Client](https://docs.aws.amazon.com/sdk-for-ruby/v3/api/Aws/S3/Client.html#initialize-instance_method) documentation.
+
 ### Microsoft Azure Storage Service
 
 Declare an Azure Storage service in `config/storage.yml`: