Add Borg Backup Server to Backups section

Borg Backup Server is a self-hosted web GUI and centralized
management dashboard for BorgBackup with agent-based architecture,
multi-server scheduling, monitoring, and file-level restore.

https://github.com/marcpope/borgbackupserver

README.md

@@ -93,6 +93,7 @@ _See also: [Restic's list of Linux backup software](https://github.com/restic/ot
 - [Bareos](https://www.bareos.org/) - Cross-network backup solution which preserves, archives, and recovers data from all major operating systems. ([Source Code](https://github.com/bareos/bareos)) `AGPL-3.0` `C++/C`
 - [Barman](https://pgbarman.org) - Backup and Recovery Manager for PostgreSQL. ([Source Code](https://github.com/EnterpriseDB/barman)) `GPL-3.0` `Python`
 - [BorgBackup](https://www.borgbackup.org/) - Deduplicating archiver with compression and authenticated encryption. ([Source Code](https://github.com/borgbackup/borg)) `BSD-3-Clause` `Python`
+- [Borg Backup Server](https://www.borgbackupserver.com/) - Self-hosted web GUI and centralized management dashboard for BorgBackup with agent-based multi-server backup scheduling, monitoring, and file-level restore. ([Source Code](https://github.com/marcpope/borgbackupserver)) `MIT` `PHP/Python`
 - [Burp](https://burp.grke.org/) - Network backup and restore program. ([Source Code](https://github.com/grke/burp)) `AGPL-3.0` `C`
 - [Dar](http://dar.linux.free.fr/) - Which stands for Disk ARchive, is a robust and rich featured archiving and backup software of the tar style. ([Source Code](https://github.com/Edrusb/DAR)) `GPL-2.0` `C++`
 - [Databasus](https://databasus.com/) - PostgreSQL, MySQL, MariaDB and MongoDB backup tool with web UI, external storages (local, S3, FTP, Google Drive, etc.), notifications (webhook, Discord, Slack, etc.) and team management. ([Source Code](https://github.com/databasus/databasus)) `Apache-2.0` `Docker`