Update docs/configuring-playbook.md: create "File Storage" section under "Authentication and user-related" section

This basically follows the order of the tables on README.md

Signed-off-by: Suguru Hirahara <acioustick@noreply.codeberg.org>

docs/configuring-playbook.md

@@ -62,12 +62,6 @@ When you're done with all the configuration you'd like to do, continue with [Ins
 
   - [Controlling Matrix federation](configuring-playbook-federation.md)
 
-- [Storing Matrix media files using matrix-media-repo](configuring-playbook-matrix-media-repo.md)
-
-- [Storing Synapse media files on Amazon S3 or another compatible Object Storage](configuring-playbook-s3.md)
-
-- [Storing Matrix media files on Amazon S3 with Goofys](docs/configuring-playbook-s3-goofys.md)
-
 - [Serving the base domain](configuring-playbook-base-domain-serving.md)
 
 ### Clients
@@ -106,6 +100,15 @@ When you're done with all the configuration you'd like to do, continue with [Ins
 
 - [Setting up Pantalaimon (E2EE aware proxy daemon)](configuring-playbook-pantalaimon.md) (advanced)
 
+### File Storage
+
+- [Storing Matrix media files on Amazon S3 with Goofys](docs/configuring-playbook-s3-goofys.md)
+
+- [Storing Synapse media files on Amazon S3 or another compatible Object Storage](configuring-playbook-s3.md)
+
+- [Storing Matrix media files using matrix-media-repo](configuring-playbook-matrix-media-repo.md)
+
+
 ### Additional useful services
 
 - [Setting up the Jitsi video-conferencing platform](configuring-playbook-jitsi.md)