Empty state for "There is nothing to merge from source branch into target branch."
Issue idea came from: https://gitlab.com/gitlab-org/gitlab-ce/issues/28558#note_25125088
Usecase
With the new `Create merge request button from https://gitlab.com/gitlab-org/gitlab-ce/issues/28558#note_25125088 people will be redirected to a merge request view with nothing in there to merge.
Problem
There is no clear way for a user to act upon a merge request view with nothing to merge.
This should improve slightly upon one of the states in https://gitlab.com/gitlab-org/gitlab-ce/issues/25424
Design
Improve empty state on merge request widget by showing the user a way to begin creating content
- CLI option
- new file gui option
- nice drawing
__spec-url:__https://gitlab-org.gitlab.io/gitlab-design/hosted/25424-Refine-MR-Widgets-spec-previews/
svg: (optimised) illustration_empty_state_mr.svg
responsive mode: Could you see if it looks great on top? otherwise hide it
Value
Clear way for people to start creating content for the merge request and be informed
Related issues
https://gitlab.com/gitlab-org/gitlab-ce/issues/28558 https://gitlab.com/gitlab-org/gitlab-ce/issues/27799 https://gitlab.com/gitlab-org/gitlab-ce/issues/25424