Super obvious, customizable project documentation link

Description

When I'm visiting a public project, I always end up looking for the documentation. Often this is in the repo, but often it is not. Finding it then requires me to scour through the readme, project description and whatnot to find the true documentation.

It would be great if GitLab had a dedicated and obvious button in each project that you can point to your documentation. This would always open in a new tab and could be a link directly to the projects' readme, wiki or an external place.

Proposal

Add a button that is easily found (for instance, whenever viewing the readme) that can be pointed to the source of documentation.

It's a good idea to show the target URL on or near the button, so it's clear that it's not pointing at some malicious site.

Documentation blurb

Different projects have different ways of doing documentation. Sometimes it's local, sometimes it's external to the repository. In all cases, making it easily discoverable by external users is key.

To make this easier, GitLab now has a dedicated link directly to the documentation of your project. By default,​ it will point to your README, but you can point it to any external URL.