Fix link to feed from blog posts

[ashwinvis]

Now, relative to root url.

The feed link in the header also vanishes in blog posts. This needs to be fixed but I am not familiar with Hugo templating:

matplotblog/themes/aether/layouts/partials/head.html

Lines 29 to 31 in 2ebc518

	{{ range .AlternativeOutputFormats -}}
	{{ printf `<link rel="%s" type="%s" href="%s" title="%s" />` .Rel .MediaType.Type .Permalink $.Site.Title | safeHTML }}
	{{ end -}}

[davidevaleriani]

This doesn't really solve the issues, but I will be pushing a fix soon.