Continuously update sankey diagram

[t0sche]

Write a workflow that will take the CVSS-BT output and generate the sankey diagram in the readme

[cwpearce]

See #34

[cwpearce]

if you like the look of what is happening in the pull request, we could look to turn it into a github action

[cwpearce]

Diagram of sankey with some manual plotly placement via browser widgets

[cwpearce]

Diagram of untouched sankey diagram (I wasn't able to work out through plotly how to control the y-axis ordering of flows based on priority:

[cwpearce]

Diagram of the bubble chart: