Add :construction: as flag for WIP merge requests
### Problem to solve
In our company, we usually use gitmoji as a basis of git documentation. Gitmoji offers :construction: (`:construction:`) for WIP changes and commits. We also want to use it for marking MR as WIP.
### Intended users
Developer
### Proposal
Now [documentation](https://docs.gitlab.com/ee/user/project/merge_requests/work_in_progress_merge_requests.html#adding-the-work-in-progress-flag-to-a-merge-request) says:
> Add `[WIP]` or `WIP:` to the start of the merge request’s title. Clicking on **Start the title with WIP:**, under the title box, when editing the merge request’s description will have the same effect.
My proposal is adding to a list with `[WIP]` and `WIP:` new item `:construction:`. It should work as other items in the WIP-flag list: disable merge button, mark MR as WIP.
### Links / references
- [Gitmoji](https://gitmoji.carloscuesta.me/)
- ["Work In Progress" merge requests](https://docs.gitlab.com/ee/user/project/merge_requests/work_in_progress_merge_requests.html#adding-the-work-in-progress-flag-to-a-merge-request)
- [Feature Highlight: WIP](https://about.gitlab.com/2016/01/08/feature-highlight-wip/)
issue