tlmgr-backup: add page (#6581)

pages/common/tlmgr-backup.md

@@ -0,0 +1,25 @@
+# tlmgr backup
+
+> Manage backups of TeX Live packages.
+> The default backup location is saved in the `backupdir` setting, which can be optained with `tlmgr option`.
+> More information: <https://www.tug.org/texlive/tlmgr.html>.
+
+- Make a backup of one or more packages:
+
+`tlmgr backup {{package1 package2 ...}}`
+
+- Make a backup of all packages:
+
+`tlmgr backup --all`
+
+- Make a backup to a specific directory:
+
+`tlmgr backup {{package}} --backupdir {{path/to/backup_directory}}`
+
+- Remove a backup of one or more packages:
+
+`tlmgr backup clean {{package1 package2 ...}}`
+
+- Remove all backups:
+
+`tlmgr backup clean --all`