Read all pages in a folder

[mDuo13]

It would be cool to specify a whole folder of files in the config so that Dactyl would read the folder and expand that into a whole list of pages. Ideally you could specify a shell-like pattern, such as *.md, so you only get the files you want.

Maybe a special type of entry in the "pages" array:

  - __dactyl_type: pageset
    md_pattern: api_methods/*.md
    category: API Methods
    targets:
        - api-ref