fix: modal content covered by background

[IlyaSemenov]

Fix #78

[jtommy]

@IlyaSemenov the problem is modal-card, following Bulma docs https://bulma.io/documentation/components/modal/#modal-card, it doesn't need that class

[IlyaSemenov]

@jtommy But the base Bulma modal needs it (quoting the link above):

The modal structure is very simple:

• modal: the main container
  • modal-background: a transparent overlay that can act as a click target to close the modal
  • modal-content: a horizontally and vertically centered container, with a maximum width of 640px, in which you can include any content
  • modal-close: a simple cross located in the top right corner

and o-modal is not supposed to be coupled with modal-card, is it?

[IlyaSemenov]

From what I gathered, modal-card can live happily inside modal-content (that's how buefy worked anyway).

[jtommy]

@IlyaSemenov thanks