Added read_wfs(), which downloads one feature type of a Berlin Geoportal
WFS service and returns it as an sf object. This complements the metadata
functions: read_metadata() says where a dataset lives, read_wfs() fetches
it. Adds sf to Imports.
Added list_wfs_layers(), which reads a service's GetCapabilities document
and returns one row per feature type. This is the authoritative way to find
out which layer to pass to read_wfs().
Added find_wfs(), which searches the catalogue read by read_metadata_all()
for records offering a download service and returns one row per matching WFS
link, including the service name that read_wfs() expects.
Added wfs_base_url() and wfs_service_name() as small helpers around the
endpoint URLs.
Added NEWS.md file to track changes to the package.
see https://style.tidyverse.org/news.html for writing a good NEWS.md