Develop documentation for how to use, maintain and update Harmonica

[tursynay]

Trish started this documentation, needs additional items included: https://github.com/include-dcc/harmonica

• Add a requirements.txt file to include which Python packages need to be installed include-linkml#240
• Add method to identify and update to new ontology version for oaklib include-linkml#241
• Include other methods to download ontology content and convert to a SQLite database using semsql include-linkml#242
• Consider whether the input data file formatting assumptions need to be parametrized in the code to handle other varieties of files, e.g. CSV or Excel files where the search data is in another sheet or the first sheet but another column. include-linkml#243