path.Dir
{{ path.Dir "a/news.html" }} → a
{{ path.Dir "news.html" }} → .
{{ path.Dir "a/b/c" }} → a/b
{{ path.Dir "/a/b/c" }} → /a/b
{{ path.Dir "/a/b/c/" }} → /a/b/c
{{ path.Dir "" }} → .
{{ path.Dir "a/news.html" }} → a
{{ path.Dir "news.html" }} → .
{{ path.Dir "a/b/c" }} → a/b
{{ path.Dir "/a/b/c" }} → /a/b
{{ path.Dir "/a/b/c/" }} → /a/b/c
{{ path.Dir "" }} → .