Scraper for Bfn legal acts

The scraper intends to fetch legal acts from BfN website.

The following pages are used to collect legal acts: *(https://www.bfn.de/bundesrecht) *(https://www.bfn.de/verordnungs-und-gesetzgebungsverfahren) *(https://www.bfn.de/weiteres-umweltrecht)

In some cases, the data provides consists mostly of a link to gesetze-im-internet.de. These are collected from the appropriate page in their own datasets.