#11 and #3 (and also #8): provided an API to the controlled vocabulary (as long as no ontology service is in place), also wrote first pytest, but not yet working (settings have to be established in test database), prepared scripts to create pages also documenting the controlled vocabulary (pages: index can still show the source code, which is wanted)

#11: still struggling with creating pdf (but now a little bit better) -- see (pandoc) command in issue

#11: started adding descriptive text for automatic openapi documentation (especially for use documenting metadata)

#3: found solution for loading controlled vocabulary only once at start time (with raw database connection); have to put it into place (so that pytests are also running); for now the workaround is still active

#4: nested download for station inside timeseries still not working properly, but at least shows some information; upload after gitlab crash

#4: nested download was extended for timeseries; TBD: showing nested station information is not working yet; also changed programme from many-to-many to 1:n

#3: added unique constraint to controlled vocabularies; added foreign keys (controlled vocabularies) to models