Is it possible to add a new wiki entry in a GitLab project using a standard merge request?

Question

Using free, self-managed GitLab

Due to group-level custom project templates available only to paid tiers (even there there are restrictions) I am looking into an alternative solution using a simple project, where

• in the code repository each branch provides a template
• in the wiki each code repository branch has an entry documenting what the template does

I know that the wiki and the code are actually two separate repositories.

In its nature a template is a construct that offers a pre-made setup for working on a reoccurring task. A group template adds the additional restriction that the reoccurring task applies to more then one individual.

In order to limit tomfoolery and people pushing whatever they want thinking it's worth becoming a group-level template (even though they made something real quick to tackle a problem that has been long forgotten and even they themselves will not work on it ever again) I would like to impose access restrictions to all members. Beside the maintainer/owner all other members are assigned a developer role. All branches are protected so a change of an existing branch or the creation of a new one can only be done through a merge request leading to an assessment whether the committed changes to the repository are actually worthy of becoming a template for the whole group.

Many members of my group have the bad habit of choosing poor names for functionality they have developed (e.g. a script called jennifers_help_script_23.py) and not documenting what was actually implemented. And yes, we are not a software development company but a research institute. :D So in order to improve the documentation and the ability to actually reuse some of the quite useful things that people have developed I would like to make it mandatory for people to provide documentation if they want their stuff to be added to the project.

So the question here is can a user submit a code merge request that also acts as a merge request for a change in the wiki (e.g. user has created a new template, which requires also a new wiki page documenting that template) or the two have to be handled separately given the nature of a GitLab project (wiki separate from code)?

I was thinking maybe each branch (representing a template) will contain a markdown file that will be inserted as a wiki automatically after the merge request has been approved. However I don't know how to automate this. I am currently looking into uploading a file to the wiki using the GitLab API, hoping a can somehow add a trigger in GitLab to execute the "command" upon a successful merge. Needless to say I am quite new to all of this.