use it like this: {{input | datapage_url: dir}} to generate a link to a data_page. the filter is smart enough to generate different link styles accor

- site and base are copied from other plugins: to be honest, I am not sure what they do - `index_files` specifies if we want to generate named folder

Ask a yes/no question via input() and return their answer. "question" is a string that is presented to the user. "default" is the presumed an