Add -d <database name> option in mongorestore because it's required as of mongo 3.0 or above

[yofriadi]

note: your documentation guideline is not found

[kay-kim]

Thank you so much for your pull request and apologies for the long delay.

I believe the documentation is correct as is. For example:

~/mongo $ mongorestore dump/
2019-07-02T13:46:31.833-0400 preparing collections to restore from
2019-07-02T13:46:31.835-0400 reading metadata for test.salaries from dump/test/salaries.metadata.json
2019-07-02T13:46:31.835-0400 reading metadata for test.purchaseorders from dump/test/purchaseorders.metadata.json
2019-07-02T13:46:31.862-0400 restoring test.salaries from dump/test/salaries.bson
2019-07-02T13:46:31.889-0400 restoring test.purchaseorders from dump/test/purchaseorders.bson
2019-07-02T13:46:31.896-0400 no indexes to restore
2019-07-02T13:46:31.896-0400 finished restoring test.salaries (10 documents)
2019-07-02T13:46:31.897-0400 no indexes to restore
2019-07-02T13:46:31.897-0400 finished restoring test.purchaseorders (6 documents)
2019-07-02T13:46:31.897-0400 restoring users from dump/admin/system.users.bson
2019-07-02T13:46:31.935-0400 restoring roles from dump/admin/system.roles.bson
2019-07-02T13:46:32.018-0400 done

As such, we will close this pull request. However, we very much appreciate your time and effort in helping us improve the docs. Once again, apologies for the long delay.

Regards,

Kay Kim