Missing z-index

[Azd325]

It would be good if can add some high z-index to the main div to prevent that elements from the page overlap the content in the frisk.

If I see it right it should be added here https://github.com/Odinodin/data-frisk-reagent/blob/master/src/datafrisk/core.cljs#L17

[Odinodin]

Sure thing, pull request welcome 👍