Adding a Safari 9.x Pinned Tab icon to my Gitlab instance, what is the best way of going about this?

I’m trying to make my Gitlab instance look good as a pinned tab in the new Mac OS X 10.11 (El Capitan) version of Safari, which now supports pinned tabs. This document explains how to do this. In brief, you have to:

  • make an SVG file of the site icon available somewhere in the webspace
  • put a <link> tag in the header of each page that points to that icon

I’ve already made my own icon in SVG format. (it’s not the greatest icon in the world, I am no graphic artist, but it’s good enough for my purpose.) So my questions are:

  • where do I put that file so that the Gitlab HTTP server can find it? (It looks like /home/git/gitlab/public/assets contains files that can be reached with URLs such as https://my.gitlab.site/assets/FILENAME. Is this a safe place to put custom images (such as the SVG icon needed for my site’s tab)? Will it be nuked when I upgrade Gitlab?
  • where do I add the <link> tag? I found the file /home/git/gitlab/app/views/layouts/_head.html.haml which appears to be the page template, and I added a line %link{rel: 'mask-icon', href: '/assets/tab.svg', color: 'red'} Is this the best way of going about this? (I assume this file could potentially get clobbered if it is changed in a future upgrade to gitlab?)

In case it makes a difference, I’ve installed Gitlab from source, not Omnibus.

Thanks!