slick: Text in contenteditable elements inside slides can't be selected (in Firefox)

What happens

The text inside a contenteditable div can’t be selected, clicked or moved around with the arrow keys.

What should happen

Elements with contenteditable elements shouldn’t be affected by using it in the page of the carousel.

Why

There is a -moz-user-select: none rule in the CSS files that applies to everything inside the whole carousel. This overrides the default value for elements with contenteditable=true.

Proposed solution

Add another rule with something like this:

.slick-slider [contenteditable] {
     -moz-user-select: text; // or all or something...
}