Wiki: Configurable maximum number of pages in the sidebar
Problem
Currently, wikis only allow a maximum of 15 pages in the sidebar, which is too little for any sizeable project. As far as I know, the restriction is in place only because of performance issues when GitLab makes use of Gitaly #17673 (comment 414478855). This, however, should not be a problem in self-hosted instances, where Gitaly either isn't used or the impact in performance is not that noticeable.
Proposal
It would be nice to make the maximum number of pages configurable, either via a setting in gitlab.rb or in the UI. I've managed to get a simple PoC working with these changes, but I'm sure it needs some work before being acceptable. Perhaps the change should only be made available on self-hosted instances.
Edited by Pablo Esteban