Usage:

1. http://pixiv.foob.dev/{path}
   - http://pixiv.foob.dev/img-original/img/0000/00/00/00/00/00/12345678_p0.png

2. http://pixiv.foob.dev/{pid}[/{p}]
   - http://pixiv.foob.dev/12345678    (p0)
   - http://pixiv.foob.dev/12345678/0  (p0)
   - http://pixiv.foob.dev/12345678/1  (p1)

3. http://pixiv.foob.dev/(original|regular|large|medium|small|thumb|mini)/{pid}[/{p}]
   - http://pixiv.foob.dev/original/12345678   (same as http://pixiv.foob.dev/12345678)
   - http://pixiv.foob.dev/regular/12345678/1  (p1, master1200)