Resolve the doc feedback (#368)

Update restore-a-backup.md

Author: alina-derkach-oaza

docs/restore-a-backup.md

@@ -1,9 +1,11 @@
-# Restore a backup
+# Restore full, incremental, and compressed backups
 
 !!! warning
 
     Backup needs to be prepared before it can be restored.
 
+The restore backup procedure is the same for full, incremental, and compressed backups.
+
 For convenience, *xtrabackup* binary has the `--copy-back` option to copy the backup to the datadir of the server:
 
 ```{.bash data-prompt="$"}