[Openstack-i18n] RFC: draft doc on how to report translation bugs

Hi team, I proposed a doc patch on how to report a translation/I18N bugs. https://review.openstack.org/#/c/246256/ It discusses which and where bugs should be filed. I know we don't have any consensus on how to manage language-specific translation bugs. My draft is just a start-line and I don't think it is best. Any discussion and input would be appreciated. Thanks, Akihiro