Simple Line Chart with Multiple lines and two different axes:
A vanilla HTML implementation of a d3Noob's V5 examples.
Examples Malcolm Maclean's (d3noob) great book "D3 Tips and Tricks v5.x Interactive Data Visualization in a Web Browser" (https://leanpub.com/d3-t-and-t-v5).
It is derived from Mike Bostock's Towards Reusable Charts (https://bost.ocks.org/mike/chart/) as the source of the foundational principles. But uses the ProD3 pattern (Pro D3.js Use D3.js to Create Maintainable, Modular, and Testable Charts by Marcos Iglesias https://www.apress.com/gp/book/9781484252024) as the basis for the charts.
Addtional help from and aknowledgement to: