Feature Suggestion

Feature description: Add MinRenderIndex MaxRenderIndex support to SignalPlot, as in v4
Needed for some of the examples here: https://scottplot.net/faq/live-data/

Some code I knocked up to do this temporarily:
https://gist.github.com/raburton/53a5838f3fa52f27ffba8d924d34848e