add prototype pre-proc and streamlit to i15-1

[keeble]

attempt to have a workflow:

• do some simple preprocessing of a nexus file from a "data collection" collection which should make a single PDF
• save the results in the processing directory (for now)
• append a line to the end of a log file, also in the processing directory

[keeble]

designed to work with https://github.com/keeble/streamlit-dashboard