Added a second example script to produce a pre-release. Here also the conversion for CoRe format is demonstrated. Renamed the previous example script.

Added a separate example file for writing index for hybrids. Diff of the two coredb_write_index_json*.py file now highlights the changes.

Added two routines to the CoRe_idx() that allows to update the index from a CoRe_md() metadata list and to write to a JSON file with specific keys from a template. Added a script to write the index JSON reading from all the metadta_data.txt of the DB

Bugfix for energy calculation, improved logic a bit (but still assumes the same modes at each extraction radius). Added more test data to have same number of modes for the two radii. Updated tutorials.

Debugged the create/read_dset h5 routines and added their use in one tutorial. These are the preferred method to create the CoRe data.h5.