add backup section (#3275)

- redirect to awesome-sysadmin
- fixes https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2668

README.md

@@ -17,6 +17,7 @@ See [Contributing](.github/CONTRIBUTING.md).
   - [Analytics](#analytics)
   - [Archiving and Digital Preservation (DP)](#archiving-and-digital-preservation-dp)
   - [Automation](#automation)
+  - [Backup](#backup)
   - [Blogging Platforms](#blogging-platforms)
   - [Booking and Scheduling](#booking-and-scheduling)
   - [Bookmarks and Link Sharing](#bookmarks-and-link-sharing)
@@ -195,6 +196,16 @@ _Related: [Internet of Things (IoT)](#internet-of-things-iot)_
 - [µTask](https://github.com/ovh/utask) - Automation engine that models and executes business processes declared in yaml. `BSD-3-Clause` `Go`
 
 
+### Backup
+
+**[`^        back to top        ^`](#)**
+
+[Backup](https://en.wikipedia.org/wiki/Backup) software.
+
+**Please visit [awesome-sysadmin/Backups](https://github.com/awesome-foss/awesome-sysadmin#backups)**
+
+
+
 ### Blogging Platforms
 
 **[`^        back to top        ^`](#)**