Add auto detection for template directories

[mvllow]

Briefly discussed in #16, we should add folder detection as well. My first thought is to simply look for a "templates" directory but then should we also look for a "template" file within or assume all files are templates? Open to suggestions.

I have not started work on this yet

[OyuDays]

i think the most sensible choice would be to just use the directory itself as the input file