Overlay plot for comparing cyclic voltammetry

[linuxrider]

The idea is to have a plotly plot and the data is pulled from csv on the server on demand on selection.

On the bottom of the CV page there is now a compare link, which leads to a overview page.
On this the desired CVs can be selected for overlaying them.
In the current state there is a mysterious delay with the selection. The previous selection (i.e. selection on click in the past) is displayed. Probably related to promises.

Addresses #177.

[linuxrider]

When using promises in a different way it works, i.e. the delay is gone.

[DunklesArchipel]

When I test this locally, I see the graph but upon selecting data it is not updated. :(

[linuxrider]

@DunklesArchipel I forgot to mention that one needs to set an environment variable.
I will change the behavior so that this is not necessary anymore.

Ok, mkdocs serve should be enough with the change.
I really like how fast this is locally. Curious how it performs on echemdb.org.

[DunklesArchipel]

Works now. I just wonder if the table in its current form is so useful. It would probably be good to have a list with identifiers to select from.

And lets see how this works when the number of entries grows even more.

[linuxrider]

Of course, the selection mechanism/table can be improved. It was not the focus for now since it should just somehow work at first.
We can discuss this further.

[saraedum]

Suggested change

	async function updatePlot(names) {
	Promise.all(
	function updatePlot(names) {
	return Promise.all(