(Volunteer) donation button on sound & pack pages

[qubodup]

I would like to support Freesound by placing donation links in all my sounds' descriptions, but I don't want to waste the time inserting the code and then having to update it, next time the campaign finishes.

I suggest that a user preference is created, which allows to add a homepage-style donation button below the license link on sound pages and below the download link on pack pages.

I hope the following images illustrate the idea well.

Settings page

Sound page

Pack page

It'd be great to implement this ASAP, since a new campaign just started and to avoid that users have to spend time manually updating the link in the description manualy.