Merge branch 'kategrechishkina-master-patch-6fe9' into 'master'

Mention Loading and Ready selectors for DAST troubleshooting

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/149600



Merged-by: Russell Dickenson <rdickenson@gitlab.com>
Co-authored-by: Kate Grechishkina <khrechyshkina@gitlab.com>