Document trigger API

We are all proud of the new commit status API and yet there are no docs for it...

https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/api/commit_statuses.rb

I'll make this a part of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/681 which I set up for 8.4.

Things to do

• Add deprecation reference in doc/ci/api/commits.md
• Add new section in: doc/api/commit.md

Related issues/MRs

• https://gitlab.com/gitlab-org/gitlab-ce/issues/3692
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/681

mentioned in issue #4768 (closed)

mentioned in merge request !2465 (merged)

Title changed from Document new commit status API to Document trigger API

Marked the task Add deprecation reference in doc/ci/api/commits.md as completed

Marked the task Add new section in: doc/api/commit.md as completed

Status changed to closed by merge request !2465 (merged)

mentioned in commit 3e65fa54