What's new:
get_related($p->related)
instead of get_related($p->tag)
category.perpage = "YourValue"
to specify the category list and set category.info = "true"
to show up the category information in your category index page.If this is an upgrade then you need to clear cache after the update process finished using the admin toolbar link to migrate your old content to new folder structure.
Old structure:
content/username/blog/file.md
New structure:
content/username/blog/category/type/file.md