Add a credential to the Credential Store

In book "How to configure server security"

chapter "3.1.2 Add a credential to the Credential Store"

revision "b2b9a9c0aaf2ac94184b8d0bc12ff1d08552d306:en-us"

There is not mentioned the credential store must exist before we want to add credential to credential store and that it can be created when adding optional parameter --create

Please add a note mentioning this.

Current example is correct because it operates with existing credential store.

For example, to add a password with the alias database-pw to the store created in the previous section