update remote-repo-infos with link to doc

was a litte confusing for me, so i added the link to the syntax-descr.

docs/configuring-playbook-backup-borg.md

@@ -56,7 +56,7 @@ where:
 
 * USER - SSH user of a provider/server
 * HOST - SSH host of a provider/server
-* REPO - borg repository name, it will be initialized on backup start, eg: `matrix`
+* REPO - borg repository name, it will be initialized on backup start, eg: `matrix`, regarding Syntax see [Remote repositories](https://borgbackup.readthedocs.io/en/stable/usage/general.html#repository-urls)
 * PASSPHRASE - passphrase used for encrypting backups, you may generate it with `pwgen -s 64 1` or use any password manager
 * PRIVATE KEY - the content of the **private** part of the SSH key you created before. The whole key (all of its belonging lines) under `matrix_backup_borg_ssh_key_private` needs to be indented with 2 spaces