bup: add page (#2454)

pages/common/bup.md

@@ -0,0 +1,23 @@
+# bup
+
+> Backup system based on the git packfile format, providing fast incremental saves and global deduplication.
+
+- Initialize a backup repository in the specified local directory:
+
+`bup -d {{path/to/repository}} init`
+
+- Prepare a given folder before taking a backup:
+
+`bup -d {{path/to/repository}} index {{path/to/folder}}`
+
+- Backup a folder to the repository:
+
+`bup -d {{path/to/repository}} save -n {{backup_name}} {{path/to/folder}}`
+
+- Show the backup snapshots currently stored in the repository:
+
+`bup -d {{path/to/repository}} ls`
+
+- Restore a specific backup snapshot to a target directory:
+
+`bup -d {{path/to/repository}} restore -C {{path/to/target_directory}} {{backup_name}}`