In dataclass attributes with an explicit setter to restrict the valid parameters are treated as having a default value by python

changed constructor of MetaData

now new notebook for obtaining sample data is running
added old version as example how a request can be generated manual

worked on documentation of code

now containing both version of notebook with conflicts. diff for
notebooks does not alwasy look nice

- added info to statistics applied during request to TOAR-DB

metadata:
- first round of documentation

added first documentation to classes and their methods

started documentation as example

fixed some typos.

added comments to produce_data example

- fixed bug in plotting of station positions

README.md
- started rework of documentation of examples

.gitignore added directory used for examples

made adoptions to the updates by Simon

- added creation of subdiretories
- added some output

Create a basic structure and added the first content