By default, when using markdown files, Cryogen will look for
`resources/templates/md/pages/*.md`. This commits allows Cryogen to fall back to
`resources/templates/pages/*.md` in the case that it can't find any files in the
former directory. It works similarly for posts and Asciidoc files.
Since we're looking specifically for `*.md` for Markdown files and `*.asc` for
Ascii files, this is an opportunity to eliminate redundancy.
