some sources don't define parameters to @source decorated functions as config-values even though it makes sense that they should be

e.g. chess-source should make players a config-value.

All example pipelines work anyways, but in the context of the dlt-project, where the example-files don't get copied over by default one ends up with error messages that some argument is not there without a way to provide it via the dlt.yml

the scope of this issue is to select most interesting sources and make sure that they work in the dlt-project