* nginx-locations.conf: Add location blocks for /browse and /package.

* guix-hpc.scm (base-layout): Adjust link to "/about".
(static-pages): Build "about/index.html" instead of "about.html".
* nginx-locations.conf (location): Add 301 redirect.

* guix-hpc.scm (post-url): Add the year and month to the post URL.
* haunt.scm (post->page): New procedure.
<top-level>: Use custom procedures instead of 'blog'.
* nginx-locations.conf: Add redirect for 'guix-hpc-debut.html'.

* getting-started.md: Add title, link to /blog.
* guix-hpc.scm (image-url, css-url): Add leading /.
(post-url): Add "/blog".
(base-layout): Add "Blog", change feed URL.
(about-page): Remove.
(static-pages)[markdown-page]: New procedure.
Use it.  Add "getting-started".
* nginx-locations.conf: Add redirects.

* nginx-locations.conf: New file.
* nginx.conf: Include it.  Remove commented out sections.