docs

docs/index.md

@@ -53,6 +53,7 @@ Each feature contains a link to the corresponding detailed feature description.
 - [SshSync](./Features/FurtherFeatures/SshSync/sshsync.md): synchronize your gpx files with a configured path on a ssh server in your local net.
 - [Software update](./Features/FurtherFeatures/SoftwareUpdate/softwareUpdate.md): Update your software
 - [file manager](./Features/FurtherFeatures/FileManager/filemanager.md): show, edit, share and delete files
+- [backup](./Features/FurtherFeatures/Backup/backup.md): backup gpx files
 
 ### Developer features
 There [application design document](./more/add.pdf) provides an extensive description documentation. Additionally these pages are available: