Update index.html.md with additional diversity info
Updated the diversity section of the handbook with information from a post on 'Inclusion' https://about.gitlab.com/culture/inclusion/
Edited by Sarrah Vesselov
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Updated the diversity section of the handbook with information from a post on 'Inclusion' https://about.gitlab.com/culture/inclusion/