config object in plot config is confusing alongside plotly.config

[jrchudy]

In plot config we have plots[0].config, plots[0].plotly.config, and plots[0].plotly.layout. These 3 properties are used to control the display and layout of plotly. Both of layout and config inside of plotly are passed directly to plotly. plots[0].config is used to override properties in plotly.layout for further customization of the plot display.

We have 2 options:

1. plots[0].config can be renamed to better communicate that it is overriding properties in plotly.layout
2. move options in plots[0].config into plotly.layout and have a list in plot code to check for them in plotly.layout to then apply the expected functionality for the custom properties

Notes:

• verify what all properties in plots[0].config do. Do they all overwrite values in plotly.layout? Are there any other cases?
• clean up plots[0].config to remove properties that were deprecated when plotly.layout was added. This will simplify the above note