Define a template for plots style

Recently @mnakh was developing some refinements for plotly. We figured out that, if we make a plot using the annotations or using a normalizing function, the plots look different.

Attached, the one with blue background is from normalizing function, the white one is from annotations.

We would like to ask you @wojasadr to decide colors, font size, and other features, so that these can be included as template when instantiating a plot. So the user will only take care of arrays and titles but not of visual things.

We can test it from my local installation if needed, thanks