mcsimport document update needed - -err_log option

Customer asking for more information on how the -err_log option works:

Does the -err_log option take a file name for the log file to create, if not, what is the name of the file it will create, and will it create it in the same directory where the file to import is located? If there are no errors is the file created with 0 bytes as long as the option is provided?

This information needs to be added to the cpimport document and is the last question a BUG or not, file size of 0 when no errors occur

Associated document

https://mariadb.com/kb/en/columnstore-remote-bulk-data-import-mcsimport/#-err_log