Joss paper review

[williamfgc]

@fanchercm I just added a few things to the JOSS paper PR for your review. Hope it helps.

Changes:

• Add authors ORCiD and affiliations
• Add bib reference to event data and HDF5
• Modify acknowledgement (funding)
• Minor changes: date, narrative
• Add definition to math symbols

[fanchercm]

Looks good for me