Should Timestamp be a Document property not a Relationship property?

[jthteo]

I envisage timestamp being related to the document rather than the relationship.
It could be stored with both node and edge of course, but storing on the node would be more succint.

medcat/neo/data_preparation.py
line 80: create_documents_csv needs timestamp: toInteger(row.timestamp), \n' moved to
line 184: create_document2conceot_csv could have timestamp removed if necessary