Keep the path of `site.baseUrl` in absolute URLs

Keep the path of site.baseUrl in absolute URLsCopy Anchor Link

Absolute URLs are now joined to site.baseUrl instead of resolved against it, so sites served from a sub-path (e.g. GitHub Pages project sites) keep it in og:image, canonical, og:url, hreflang links, sitemap entries, the robots Sitemap entry and RSS links. Before, https://user.github.io/repo produced https://user.github.io/index.webp instead of https://user.github.io/repo/index.webp.

The RSS <link rel="alternate"> now includes basePath too.