Should this PR also update or remove _images/favicon32x32.png ?

I don't know why you have this file here, favicons are always ico files and are already 32x32. So, it's useless to build the website as favicon, but maybe you used it for something else? If not, yes, you can kick it :)

Just saw, you use the png file here:

_templates/page.html.erb: <link href="<%= File.join(images_path, "favicon32x32.png") %>" rel="shortcut icon" type="text/css">

I rely on your expertise in this regard :)

Replaced by PR #39