🚀 Feature: Add a footer promoting Open Source

[avesst]

🔖 Feature description

Add a footer (maybe configurable through toggle on/off?) that says something like "Made possible through Open Source" (or something) and a link to this Github.

🎤 Pitch

I plan on running this as a file sharing service in a public sector environment in one of Swedens larger municipalities (12k potential users) and would like to promote Open Source as well as give credit to the project if I rebrand :)