Merge branch 'master' of https://github.com/syuilo/misskey

docs/backup.md

@@ -7,7 +7,7 @@ Make sure **mongodb-tools** installed.
 
 In your shell:
 ``` shell
-$ mongodump --archive=db-backup
+$ mongodump --archive=db-backup -u <YourUserName> -p <YourPassword>
 ```
 
 For details, plese see [mongodump docs](https://docs.mongodb.com/manual/reference/program/mongodump/).