Improve the grammar of the API docs
See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html
What does this MR do?
Fixes some grammar and clarifies the Project API docs.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
See the general Documentation guidelines http://docs.gitlab.com/ce/development/doc_styleguide.html
Fixes some grammar and clarifies the Project API docs.